A phase of the ESTROUS CYCLES that follows METESTRUS. Diestrus is a period of sexual quiescence separating phases of ESTRUS in polyestrous animals.
The period in the ESTROUS CYCLE associated with maximum sexual receptivity and fertility in non-primate female mammals.
The period of cyclic physiological and behavior changes in non-primate female mammals that exhibit ESTRUS. The estrous cycle generally consists of 4 or 5 distinct periods corresponding to the endocrine status (PROESTRUS; ESTRUS; METESTRUS; DIESTRUS; and ANESTRUS).
The period following ESTRUS during which the phenomena of estrus subside in those animals in which pregnancy or pseudopregnancy does not occur.
A phase of the ESTROUS CYCLE that precedes ESTRUS. During proestrus, the Graafian follicles undergo maturation.
The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.
The surgical removal of one or both ovaries.
The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids.
The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.
The hollow thick-walled muscular organ in the female PELVIS. It consists of the fundus (the body) which is the site of EMBRYO IMPLANTATION and FETAL DEVELOPMENT. Beyond the isthmus at the perineal end of fundus, is CERVIX UTERI (the neck) opening into VAGINA. Beyond the isthmi at the upper abdominal end of fundus, are the FALLOPIAN TUBES.
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.
The yellow body derived from the ruptured OVARIAN FOLLICLE after OVULATION. The process of corpus luteum formation, LUTEINIZATION, is regulated by LUTEINIZING HORMONE.
A lactogenic hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). It is a polypeptide of approximately 23 kD. Besides its major action on lactation, in some species prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation and osmoregulation. Prolactin receptors are present in the mammary gland, hypothalamus, liver, ovary, testis, and prostate.
The process of bearing developing young (EMBRYOS or FETUSES) in utero in non-human mammals, beginning from FERTILIZATION to BIRTH.
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
The genital canal in the female, extending from the UTERUS to the VULVA. (Stedman, 25th ed)
The discharge of an OVUM from a rupturing follicle in the OVARY.
An acyclic state that resembles PREGNANCY in that there is no ovarian cycle, ESTROUS CYCLE, or MENSTRUAL CYCLE. Unlike pregnancy, there is no EMBRYO IMPLANTATION. Pseudopregnancy can be experimentally induced to form DECIDUOMA in the UTERUS.
Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.
Labile proteins on or in prolactin-sensitive cells that bind prolactin initiating the cells' physiological response to that hormone. Mammary casein synthesis is one of the responses. The receptors are also found in placenta, liver, testes, kidneys, ovaries, and other organs and bind and respond to certain other hormones and their analogs and antagonists. This receptor is related to the growth hormone receptor.
A decapeptide that stimulates the synthesis and secretion of both pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE. GnRH is produced by neurons in the septum PREOPTIC AREA of the HYPOTHALAMUS and released into the pituitary portal blood, leading to stimulation of GONADOTROPHS in the ANTERIOR PITUITARY GLAND.
The mucous membrane lining of the uterine cavity that is hormonally responsive during the MENSTRUAL CYCLE and PREGNANCY. The endometrium undergoes cyclic changes that characterize MENSTRUATION. After successful FERTILIZATION, it serves to sustain the developing embryo.
An OOCYTE-containing structure in the cortex of the OVARY. The oocyte is enclosed by a layer of GRANULOSA CELLS providing a nourishing microenvironment (FOLLICULAR FLUID). The number and size of follicles vary depending on the age and reproductive state of the female. The growing follicles are divided into five stages: primary, secondary, tertiary, Graafian, and atretic. Follicular growth and steroidogenesis depend on the presence of GONADOTROPINS.
Any suction exerted by the mouth; response of the mammalian infant to draw milk from the breast. Includes sucking on inanimate objects. Not to be used for thumb sucking, which is indexed under fingersucking.
Compounds that interact with ESTROGEN RECEPTORS in target tissues to bring about the effects similar to those of ESTRADIOL. Estrogens stimulate the female reproductive organs, and the development of secondary female SEX CHARACTERISTICS. Estrogenic chemicals include natural, synthetic, steroidal, or non-steroidal compounds.
The anterior glandular lobe of the pituitary gland, also known as the adenohypophysis. It secretes the ADENOHYPOPHYSEAL HORMONES that regulate vital functions such as GROWTH; METABOLISM; and REPRODUCTION.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Steroid hormones produced by the GONADS. They stimulate reproductive organs, germ cell maturation, and the secondary sex characteristics in the males and the females. The major sex steroid hormones include ESTRADIOL; PROGESTERONE; and TESTOSTERONE.
The degeneration and resorption of an OVARIAN FOLLICLE before it reaches maturity and ruptures.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.
The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.
Surgical removal or artificial destruction of gonads.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
Gonadotropins secreted by the pituitary or the placenta in horses. This term generally refers to the gonadotropins found in the pregnant mare serum, a rich source of equine CHORIONIC GONADOTROPIN; LUTEINIZING HORMONE; and FOLLICLE STIMULATING HORMONE. Unlike that in humans, the equine LUTEINIZING HORMONE, BETA SUBUNIT is identical to the equine choronic gonadotropin, beta. Equine gonadotropins prepared from pregnant mare serum are used in reproductive studies.
A pair of highly specialized muscular canals extending from the UTERUS to its corresponding OVARY. They provide the means for OVUM collection, and the site for the final maturation of gametes and FERTILIZATION. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three histologic layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells.

Abnormal estrous cyclicity after disruption of endothelial and inducible nitric oxide synthase in mice. (1/173)

The roles of nitric oxide (NO) and nitric oxide synthase (NOS) in reproduction were studied by examining the estrous cycle of wild-type (WT) mice, inducible NOS (iNOS)-, and endothelial NOS (eNOS)-knockout mice. We observed an average estrous cycle of 4.8 +/- 0.2 days in WT mice. While we observed no significant influence of iNOS deficiency on cycle length, eNOS-knockout females showed a significantly longer estrous cycle (6.6 +/- 0.6 days; p < 0.03) than WT females, due to an extension of diestrus (p < 0.03). There was no influence of iNOS deficiency on ovulation rate compared with that in WT females; however, eNOS-knockout mice showed a significant reduction (p < 0.05) in ovulatory efficiency relative to WT or iNOS-knockout females. In contrast to WT females, in which the highest level of estradiol (E2) was observed at 1500 h of proestrus, iNOS-knockout females reached a peak of E2 at 1830 h of proestrus. In eNOS-knockout females, the peak of E2 occurred at 1830 h, as in iNOS-knockout mice; however, E2 levels were 5-fold and 3-fold higher (p < 0.05) than levels observed in WT and iNOS-knockout females, respectively. There was no effect of genotype on the plasma LH concentrations at proestrus. On the first day of diestrus, eNOS-knockout females showed significantly higher plasma E2 and progesterone levels (p < 0.05) relative to WT and iNOS-knockout females. The dysfunction in cyclicity, ovulation rate, ovarian morphology, and steroidogenesis in eNOS-knockout female mice strongly supports the concept that eNOS/NO plays critical roles in ovulation and follicular development.  (+info)

Increased expression of both short and long forms of prolactin receptor mRNA in hypothalamic nuclei of lactating rats. (2/173)

This study investigated expression of prolactin receptor (PRL-R) mRNA in selected hypothalamic nuclei of lactating rats (days 7-10 post partum) compared with dioestrous rats. Rat brains were frozen with liquid nitrogen and cut into coronal sections of 300 microm. From these sections, tissues were micropunched from the parietal cortex (CTX), choroid plexus (ChP), and five hypothalamic regions: supraoptic (SO), paraventricular (Pa), arcuate (Arc) and ventromedial hypothalamic (VMH) nuclei, and median eminence (ME). Expression of both short and long forms of PRL-R mRNA were evaluated by reverse transcription-PCR and Southern hybridisation. The results showed that the relative amount of short form mRNA in the ChP of lactating rats was significantly higher than in dioestrous rats. The short form of PRL-R mRNA was undetectable in the SO, Pa, VMH of dioestrous rats but was expressed at a significant level in lactating rats. Levels of long form mRNA in the ChP, SO, Pa and VMH in lactating rats were significantly increased compared with dioestrous rats. Moreover, the long form mRNA was induced in the CTX of lactating rats. In the Arc, levels of both forms of PRL-R mRNA tended to increase in lactating rats compared with dioestrous rats but changes were not statistically significant. Neither form of PRL-R mRNA was detectable in the ME in the two animal models. Increased expression of PRL-R mRNA in specific brain regions during lactation is consistent with the variety of PRL effects on the brain, and may help to explain profound physiological changes in the lactating mother.  (+info)

A comparison of brain angiotensin II receptors during lactation and diestrus of the estrous cycle in the rat. (3/173)

During lactation there are many dramatic alterations in the hypothalamic-pituitary (HP) axis, as well as an increased demand for food and water. The renin-angiotensin system (RAS) is one of the major mediators of the HP axis. This study examined the receptors for ANG II in the rat brain during lactation and diestrus. Compared with diestrus, lactating rats had significant decreases in ANG II receptor binding in several forebrain regions, most notably in the arcuate nucleus/median eminence, dorsomedial hypothalamic nucleus (DMH), and lateral hypothalamic area (LHA). In contrast, there was an increase in ANG II receptor binding in the preoptic area during lactation. These significant changes in ANG II binding in the brain during lactation support the hypothesis that changes in the RAS may contribute to the dramatic changes in the HP axis during lactation. In addition, the significant reduction in ANG II binding in the DMH and LHA may be indicative of a role in the regulation of food intake, a function only recently associated with the RAS.  (+info)

Dual control of cytochrome-c oxidase activity by female sex steroids. (4/173)

Female sex steroids modify cytochrome-c oxidase (COX) activity in brown adipose tissue. To check the possibility of extending this modulating effect upon oxidative capacity to other tissues, COX activity was measured in different tissues from cold-acclimated female rats that were (1) intact in proestrus and diestrus I, (2) ovariectomized or (3) ovariectomized and treated with oestradiol and/or progesterone. In intact rats, COX activity varied within the oestrous cycle in brown adipose tissue and soleus muscle. Ovariectomy induced an increase in COX activity in most of the tissues studied, an increase reversed only after 10 days of treatment with oestradiol and/or progesterone. These results indicate both a short-term (oestrous cycle) and a long-term (ovariectomy) control of COX activity by female sex steroids, probably mediated by allosteric modulation and control of the enzyme synthesis respectively. In thermogenic tissues, that is brown adipose tissue and skeletal muscles, the short-term control is interpreted as a cooperation between tissues to fulfil the requirements of temperature maintenance.  (+info)

Use of a small dose of estradiol benzoate during diestrus to synchronize development of the ovulatory follicle in cattle. (5/173)

We tested the hypothesis that a small dose of estradiol benzoate (EB) at the midstage of the estrous cycle in cattle would synchronize the subsequent pattern of ovarian follicular development, estrus, and ovulation. Nonlactating Friesian cows received either 1 mg of EB i.m. on d 13 of the estrous cycle (T; n = 12; estrus = d0) or served as untreated controls (C; n = 12). Their ovaries were examined daily with transrectal ultrasonography from d 7, and blood samples were collected 0, 2, 4, 8, 24, and 48 h after treatment on d 13. Plasma concentrations of estradiol-17beta were elevated to 12 pg/mL during the initial 24 h following treatment, compared with a baseline of 1 pg/mL in untreated controls (P < .001). Progesterone concentrations in cows of the T group declined between 24 and 48 h after treatment (-3.2 +/- .5 ng/mL) compared with little change in concentrations of progesterone in cows of the C group at this time (P < .01). This difference was coincident with an earlier time to regression of the corpus luteum in cows of the T group. Disregarding treatment groups, the second dominant follicle of the estrous cycle (DF2) emerged on d 10.6 +/- .3 and was 9.4 +/- .4 mm in diameter on d 13. Further growth of the DF2 was halted by EB treatment on d 13. Cessation of growth occurred irrespective of whether the DF2 was in the early or late growth phase, and a new follicular wave emerged 4.5 +/- .2 d later. The dominant follicle from this wave (DF3) ovulated 5 d after emergence in most cases. During the estrous cycle of every cow in the T group, there were three waves of follicular development (3-wave), whereas the ratio of 2:3 waves of follicular development in cows of the C group was 1:3. Consequently, the interval from emergence to ovulation of the ovulatory dominant follicle in cows of the C group ranged from 3 to 11 d. The dynamics of ovarian follicular wave development during the estrous cycle can be strategically manipulated by treating with a small dose of EB to synchronize proestrous development of the ovulatory follicle.  (+info)

Hormonal variation of rat uterine contractile responsiveness to selective neurokinin receptor agonists. (6/173)

Regulated uterine contractions are important in many reproductive functions such as sperm transport and embryo positioning during implantation. The role of classical neurotransmitters including acetylcholine and norepinephrine in regulating myometrial contractility has been well studied; however, the peripheral role of sensory neurotransmitters such as the neurokinins is less clear. The major neurokinins are substance P, neurokinin A, and neurokinin B, which predominantly activate neurokinin receptors (NK-Rs) 1, 2, and 3, respectively. This study utilized selective receptor agonists to examine the role of NK-Rs in uterine contractility. Uterine tissues, obtained from the major stages of the rat estrous cycle, were stimulated with selective NK-R agonists. Addition of each agonist resulted in a significant contractile response. However, the magnitude and nature of the response were dependent upon the stage of the estrous cycle, with responses to all agonists being significantly decreased in tissue from proestrus and estrus. Furthermore, the nature of NK3-R-mediated contraction was different in tissue from proestrus and estrus compared to metestrus and diestrus. The hormonal dependence of NK-R-mediated contractility was then examined in the ovariectomized estrogen-supplemented rat model. These studies confirmed that the magnitude and nature of uterine contractility in response to NK-R activation depend upon the hormonal environment.  (+info)

Fine structural changes in uterine smooth muscle and fibroblasts in response to estrogen. (7/173)

The fine structure of the estrogen-primed uterus was examined in two series of rats, with emphasis upon the alterations in smooth muscle cells and fibroblasts. The first series of animals were mature animals that were sacrificed at diestrus or estrus. The second series consisted of prepubertal rats (57-70 g) that received subcutaneous injections of estradiol-17 beta in 20% alcohol. Four groups of animals received the hormone twice daily for 3 days for a total dose of 0.06, 0.6, 6.0, or 60.0 microg, respectively. An estrogenic response was observed in all groups as indicated by an increase in uterine weight. Control groups consisted of either untreated animals or animals receiving 20% alcohol. All animals were sacrificed on the 4th day. The fibroblasts and smooth muscle cells in the controls were similar to their counterparts in the mature animal in diestrus. They were small, contained relatively little rough endoplasmic reticulum, and the connective tissue cells appeared like fibrocytes. All of the estrogen-treated animals were similar in appearance and were comparable to their counterparts in the mature animal in estrus. Both the smooth muscle cells and the fibroblasts were increased in size, demonstrated a marked enlargement and dilation of ergastoplasmic cisternae, and contained increased numbers of attached and free cytoplasmic ribosomes. The presence of an extensive rough endoplasmic reticulum in the smooth muscle cells of the stimulated uterus is in marked contrast to the appearance of these cells in other tissues. These observations correlate with previous biochemical studies by other workers, in which estrogens have been shown to promote the synthesis of uterine RNA, collagen, and noncollagenous protein, and suggest that smooth muscle cells may participate in the synthesis of connective tissue proteins.  (+info)

Estrous changes in responses of rat gracile nucleus neurons to stimulation of skin and pelvic viscera. (8/173)

Multi- and single-unit recording was performed in the gracile nucleus in urethane-anesthetized rats to examine estrous variations in responses of its neurons to brushing the hindquarters and mechanical stimulation of the uterus, vaginal canal, cervix, and colon. Six rats each were studied in each of the four estrous stages: proestrus (P), estrus (E), metestrus (M), and diestrus (D). The magnitude of multi-unit responses to gentle brushing of the perineum, hip, and tail, but not the foot and leg, was significantly greater during proestrus than during other stages. Of 70 single units responsive to brush, 56 (80%) responded to stimulation of at least one viscus. Although this percentage did not change with estrous stage, the direction and latency of some responses did. Pressure on the cervix evoked significantly more inhibitory (vs excitatory) responses in P than in E and M, and the response latency was significantly longer in D and P than in E and M. The direction of response to vaginal distention did not change with estrous stage, but response latency was significantly longer in D than in P and E. Uterine distention evoked significantly more inhibitory responses in D than in P, with no estrous changes in latency. Responses to colon distention did not change. These variations in both magnitude of response to tactile stimulation and characteristics of response to stimulation of reproductive organs, but not the colon, correlate with changes in mating behaviors of the female rat, suggesting that the gracile nucleus is a component of neural systems that control reproductive behaviors.  (+info)

Diestrus is a stage in the estrous cycle of animals, which is similar to the menstrual cycle in humans. It follows the phase of estrus (or heat), during which the animal is receptive to mating. Diestrus is the period of relative sexual quiescence and hormonal stability between cycles. In this phase, the corpus luteum in the ovary produces progesterone, preparing the uterus for potential pregnancy. If fertilization does not occur, the corpus luteum will degenerate, leading to a drop in progesterone levels and the onset of the next estrous cycle. The duration of diestrus varies among species.

In humans, this phase is analogous to the luteal phase of the menstrual cycle. However, since humans do not exhibit estrous behavior, the term 'diestrus' is typically not used in human reproductive physiology discussions.

Estrus is a term used in veterinary medicine to describe the physiological and behavioral state of female mammals that are ready to mate and conceive. It refers to the period of time when the female's reproductive system is most receptive to fertilization.

During estrus, the female's ovaries release one or more mature eggs (ovulation) into the fallopian tubes, where they can be fertilized by sperm from a male. This phase of the estrous cycle is often accompanied by changes in behavior and physical appearance, such as increased vocalization, restlessness, and swelling of the genital area.

The duration and frequency of estrus vary widely among different species of mammals. In some animals, such as dogs and cats, estrus occurs regularly at intervals of several weeks or months, while in others, such as cows and mares, it may only occur once or twice a year.

It's important to note that the term "estrus" is not used to describe human reproductive physiology. In humans, the equivalent phase of the menstrual cycle is called ovulation.

The estrous cycle is the reproductive cycle in certain mammals, characterized by regular changes in the reproductive tract and behavior, which are regulated by hormonal fluctuations. It is most commonly observed in non-primate mammals such as dogs, cats, cows, pigs, and horses.

The estrous cycle consists of several stages:

1. Proestrus: This stage lasts for a few days and is characterized by the development of follicles in the ovaries and an increase in estrogen levels. During this time, the female may show signs of sexual receptivity, but will not allow mating to occur.
2. Estrus: This is the period of sexual receptivity, during which the female allows mating to take place. It typically lasts for a few days and is marked by a surge in luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which triggers ovulation.
3. Metestrus: This stage follows ovulation and is characterized by the formation of a corpus luteum, a structure that produces progesterone to support pregnancy. If fertilization does not occur, the corpus luteum will eventually regress, leading to the next phase.
4. Diestrus: This is the final stage of the estrous cycle and can last for several weeks or months. During this time, the female's reproductive tract returns to its resting state, and she is not sexually receptive. If pregnancy has occurred, the corpus luteum will continue to produce progesterone until the placenta takes over this function later in pregnancy.

It's important to note that the human menstrual cycle is different from the estrous cycle. While both cycles involve hormonal fluctuations and changes in the reproductive tract, the menstrual cycle includes a shedding of the uterine lining (menstruation) if fertilization does not occur, which is not a feature of the estrous cycle.

Metestrus is the second phase of the estrous cycle in animals, specifically referring to the period of sexual receptivity and ovulation. In humans, this phase corresponds to the luteal phase of the menstrual cycle. During metestrus, the corpus luteum, a temporary endocrine structure formed from the remains of the ovarian follicle after ovulation, produces progesterone, which prepares the uterus for potential implantation of a fertilized egg. The duration of metestrus varies among species and can last several days to a few weeks. It is followed by diestrus, the final phase of the estrous cycle, during which the corpus luteum regresses, and hormone levels drop, leading to the shedding of the uterine lining in non-pregnant individuals.

Proestrus is a stage in the estrous cycle of animals, specifically referring to the phase preceding estrus (heat) during which follicle development and estrogen production occur. It is characterized by the swelling of the vulva and the onset of behaviors indicating readiness to mate, although the animal is not yet receptive to males. This stage typically lasts around 2-13 days, depending on the species. In humans, this equivalent phase does not exist due to menstrual cycles rather than estrous cycles.

Progesterone is a steroid hormone that is primarily produced in the ovaries during the menstrual cycle and in pregnancy. It plays an essential role in preparing the uterus for implantation of a fertilized egg and maintaining the early stages of pregnancy. Progesterone works to thicken the lining of the uterus, creating a nurturing environment for the developing embryo.

During the menstrual cycle, progesterone is produced by the corpus luteum, a temporary structure formed in the ovary after an egg has been released from a follicle during ovulation. If pregnancy does not occur, the levels of progesterone will decrease, leading to the shedding of the uterine lining and menstruation.

In addition to its reproductive functions, progesterone also has various other effects on the body, such as helping to regulate the immune system, supporting bone health, and potentially influencing mood and cognition. Progesterone can be administered medically in the form of oral pills, intramuscular injections, or vaginal suppositories for various purposes, including hormone replacement therapy, contraception, and managing certain gynecological conditions.

Ovariectomy is a surgical procedure in which one or both ovaries are removed. It is also known as "ovary removal" or "oophorectomy." This procedure is often performed as a treatment for various medical conditions, including ovarian cancer, endometriosis, uterine fibroids, and pelvic pain. Ovariectomy can also be part of a larger surgical procedure called an hysterectomy, in which the uterus is also removed.

In some cases, an ovariectomy may be performed as a preventative measure for individuals at high risk of developing ovarian cancer. This is known as a prophylactic ovariectomy. After an ovariectomy, a person will no longer have menstrual periods and will be unable to become pregnant naturally. Hormone replacement therapy may be recommended in some cases to help manage symptoms associated with the loss of hormones produced by the ovaries.

Estradiol is a type of estrogen, which is a female sex hormone. It is the most potent and dominant form of estrogen in humans. Estradiol plays a crucial role in the development and maintenance of secondary sexual characteristics in women, such as breast development and regulation of the menstrual cycle. It also helps maintain bone density, protect the lining of the uterus, and is involved in cognition and mood regulation.

Estradiol is produced primarily by the ovaries, but it can also be synthesized in smaller amounts by the adrenal glands and fat cells. In men, estradiol is produced from testosterone through a process called aromatization. Abnormal levels of estradiol can contribute to various health issues, such as hormonal imbalances, infertility, osteoporosis, and certain types of cancer.

An ovary is a part of the female reproductive system in which ova or eggs are produced through the process of oogenesis. They are a pair of solid, almond-shaped structures located one on each side of the uterus within the pelvic cavity. Each ovary measures about 3 to 5 centimeters in length and weighs around 14 grams.

The ovaries have two main functions: endocrine (hormonal) function and reproductive function. They produce and release eggs (ovulation) responsible for potential fertilization and development of an embryo/fetus during pregnancy. Additionally, they are essential in the production of female sex hormones, primarily estrogen and progesterone, which regulate menstrual cycles, sexual development, and reproduction.

During each menstrual cycle, a mature egg is released from one of the ovaries into the fallopian tube, where it may be fertilized by sperm. If not fertilized, the egg, along with the uterine lining, will be shed, leading to menstruation.

The uterus, also known as the womb, is a hollow, muscular organ located in the female pelvic cavity, between the bladder and the rectum. It has a thick, middle layer called the myometrium, which is composed of smooth muscle tissue, and an inner lining called the endometrium, which provides a nurturing environment for the fertilized egg to develop into a fetus during pregnancy.

The uterus is where the baby grows and develops until it is ready for birth through the cervix, which is the lower, narrow part of the uterus that opens into the vagina. The uterus plays a critical role in the menstrual cycle as well, by shedding its lining each month if pregnancy does not occur.

Luteinizing Hormone (LH) is a glycoprotein hormone, which is primarily produced and released by the anterior pituitary gland. In women, a surge of LH triggers ovulation, the release of an egg from the ovaries during the menstrual cycle. During pregnancy, LH stimulates the corpus luteum to produce progesterone. In men, LH stimulates the testes to produce testosterone. It plays a crucial role in sexual development, reproduction, and maintaining the reproductive system.

The corpus luteum is a temporary endocrine structure that forms in the ovary after an oocyte (egg) has been released from a follicle during ovulation. It's formed by the remaining cells of the ruptured follicle, which transform into large, hormone-secreting cells.

The primary function of the corpus luteum is to produce progesterone and, to a lesser extent, estrogen during the menstrual cycle or pregnancy. Progesterone plays a crucial role in preparing the uterus for potential implantation of a fertilized egg and maintaining the early stages of pregnancy. If pregnancy does not occur, the corpus luteum will typically degenerate and stop producing hormones after approximately 10-14 days, leading to menstruation.

However, if pregnancy occurs, the developing embryo starts to produce human chorionic gonadotropin (hCG), which signals the corpus luteum to continue secreting progesterone and estrogen until the placenta takes over hormonal production, usually around the end of the first trimester.

Prolactin is a hormone produced by the pituitary gland, a small gland located at the base of the brain. Its primary function is to stimulate milk production in women after childbirth, a process known as lactation. However, prolactin also plays other roles in the body, including regulating immune responses, metabolism, and behavior. In men, prolactin helps maintain the sexual glands and contributes to paternal behaviors.

Prolactin levels are usually low in both men and non-pregnant women but increase significantly during pregnancy and after childbirth. Various factors can affect prolactin levels, including stress, sleep, exercise, and certain medications. High prolactin levels can lead to medical conditions such as amenorrhea (absence of menstruation), galactorrhea (spontaneous milk production not related to childbirth), infertility, and reduced sexual desire in both men and women.

"Animal pregnancy" is not a term that is typically used in medical definitions. However, in biological terms, animal pregnancy refers to the condition where a fertilized egg (or eggs) implants and develops inside the reproductive tract of a female animal, leading to the birth of offspring (live young).

The specific details of animal pregnancy can vary widely between different species, with some animals exhibiting phenomena such as placental development, gestation periods, and hormonal changes that are similar to human pregnancy, while others may have very different reproductive strategies.

It's worth noting that the study of animal pregnancy and reproduction is an important area of biological research, as it can provide insights into fundamental mechanisms of embryonic development, genetics, and evolution.

Pregnancy is a physiological state or condition where a fertilized egg (zygote) successfully implants and grows in the uterus of a woman, leading to the development of an embryo and finally a fetus. This process typically spans approximately 40 weeks, divided into three trimesters, and culminates in childbirth. Throughout this period, numerous hormonal and physical changes occur to support the growing offspring, including uterine enlargement, breast development, and various maternal adaptations to ensure the fetus's optimal growth and well-being.

The vagina is the canal that joins the cervix (the lower part of the uterus) to the outside of the body. It also is known as the birth canal because babies pass through it during childbirth. The vagina is where sexual intercourse occurs and where menstrual blood exits the body. It has a flexible wall that can expand and retract. During sexual arousal, the vaginal walls swell with blood to become more elastic in order to accommodate penetration.

It's important to note that sometimes people use the term "vagina" to refer to the entire female genital area, including the external structures like the labia and clitoris. But technically, these are considered part of the vulva, not the vagina.

Ovulation is the medical term for the release of a mature egg from an ovary during a woman's menstrual cycle. The released egg travels through the fallopian tube where it may be fertilized by sperm if sexual intercourse has occurred recently. If the egg is not fertilized, it will break down and leave the body along with the uterine lining during menstruation. Ovulation typically occurs around day 14 of a 28-day menstrual cycle, but the timing can vary widely from woman to woman and even from cycle to cycle in the same woman.

During ovulation, there are several physical changes that may occur in a woman's body, such as an increase in basal body temperature, changes in cervical mucus, and mild cramping or discomfort on one side of the lower abdomen (known as mittelschmerz). These symptoms can be used to help predict ovulation and improve the chances of conception.

It's worth noting that some medical conditions, such as polycystic ovary syndrome (PCOS) or premature ovarian failure, may affect ovulation and make it difficult for a woman to become pregnant. In these cases, medical intervention may be necessary to help promote ovulation and increase the chances of conception.

Pseudopregnancy, also known as pseudocyesis or phantom pregnancy, is a psychological condition where an individual (most commonly in women) believes they are pregnant when they are not. This belief is often accompanied by various physical symptoms such as weight gain, abdominal distention, and breast enlargement that mimic those of a genuine pregnancy, despite there being no actual fetal development. These symptoms are caused by the body's hormonal and physiological responses to the individual's strong belief of being pregnant. It is important to note that this condition is rare and can be resolved with proper medical evaluation, counseling, and support.

I'm sorry for any confusion, but "horses" is not a medical term. It is the common name given to the species *Equus ferus caballus*, which are large domesticated mammals used for transportation, work, and recreation. If you have any questions about horses or a related topic that you would like a medical perspective on, please let me know and I'd be happy to help!

Follicle-Stimulating Hormone (FSH) is a glycoprotein hormone secreted and released by the anterior pituitary gland. In females, it promotes the growth and development of ovarian follicles in the ovary, which ultimately leads to the maturation and release of an egg (ovulation). In males, FSH stimulates the testes to produce sperm. It works in conjunction with luteinizing hormone (LH) to regulate reproductive processes. The secretion of FSH is controlled by the hypothalamic-pituitary-gonadal axis and its release is influenced by the levels of gonadotropin-releasing hormone (GnRH), estrogen, inhibin, and androgens.

Prolactin receptors are proteins found on the surface of various cells throughout the body that bind to the hormone prolactin. Once prolactin binds to its receptor, it activates a series of intracellular signaling pathways that regulate diverse physiological functions, including lactation, growth and development, metabolism, immune function, and behavior.

Prolactin receptors belong to the class I cytokine receptor family and are expressed in many tissues, including the mammary gland, pituitary gland, liver, kidney, adipose tissue, brain, and immune cells. In the mammary gland, prolactin signaling through its receptor is essential for milk production and breast development during pregnancy and lactation.

Abnormalities in prolactin receptor function have been implicated in several diseases, including cancer, infertility, and metabolic disorders. Therefore, understanding the structure, regulation, and function of prolactin receptors is crucial for developing new therapies to treat these conditions.

Gonadotropin-Releasing Hormone (GnRH), also known as Luteinizing Hormone-Releasing Hormone (LHRH), is a hormonal peptide consisting of 10 amino acids. It is produced and released by the hypothalamus, an area in the brain that links the nervous system to the endocrine system via the pituitary gland.

GnRH plays a crucial role in regulating reproduction and sexual development through its control of two gonadotropins: follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These gonadotropins, in turn, stimulate the gonads (ovaries or testes) to produce sex steroids and eggs or sperm.

GnRH acts on the anterior pituitary gland by binding to its specific receptors, leading to the release of FSH and LH. The hypothalamic-pituitary-gonadal axis is under negative feedback control, meaning that when sex steroid levels are high, they inhibit the release of GnRH, which subsequently decreases FSH and LH secretion.

GnRH agonists and antagonists have clinical applications in various medical conditions, such as infertility treatments, precocious puberty, endometriosis, uterine fibroids, prostate cancer, and hormone-responsive breast cancer.

The endometrium is the innermost layer of the uterus, which lines the uterine cavity and has a critical role in the menstrual cycle and pregnancy. It is composed of glands and blood vessels that undergo cyclic changes under the influence of hormones, primarily estrogen and progesterone. During the menstrual cycle, the endometrium thickens in preparation for a potential pregnancy. If fertilization does not occur, it will break down and be shed, resulting in menstruation. In contrast, if implantation takes place, the endometrium provides essential nutrients to support the developing embryo and placenta throughout pregnancy.

An ovarian follicle is a fluid-filled sac in the ovary that contains an immature egg or ovum (oocyte). It's a part of the female reproductive system and plays a crucial role in the process of ovulation.

Ovarian follicles start developing in the ovaries during fetal development, but only a small number of them will mature and release an egg during a woman's reproductive years. The maturation process is stimulated by hormones like follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

There are different types of ovarian follicles, including primordial, primary, secondary, and tertiary or Graafian follicles. The Graafian follicle is the mature follicle that ruptures during ovulation to release the egg into the fallopian tube, where it may be fertilized by sperm.

It's important to note that abnormal growth or development of ovarian follicles can lead to conditions like polycystic ovary syndrome (PCOS) and ovarian cancer.

"Sucking behavior" is not a term typically used in medical terminology. However, in the context of early childhood development and behavior, "non-nutritive sucking" is a term that may be used to describe an infant or young child's habitual sucking on their thumb, fingers, or pacifiers, beyond what is necessary for feeding. This type of sucking behavior can provide a sense of security, comfort, or help to self-soothe and manage stress or anxiety.

It's important to note that while non-nutritive sucking is generally considered a normal part of early childhood development, persistent sucking habits beyond the age of 2-4 years may lead to dental or orthodontic problems such as an overbite or open bite. Therefore, it's recommended to monitor and address these behaviors if they persist beyond this age range.

Estrogens are a group of steroid hormones that are primarily responsible for the development and regulation of female sexual characteristics and reproductive functions. They are also present in lower levels in males. The main estrogen hormone is estradiol, which plays a key role in promoting the growth and development of the female reproductive system, including the uterus, fallopian tubes, and breasts. Estrogens also help regulate the menstrual cycle, maintain bone density, and have important effects on the cardiovascular system, skin, hair, and cognitive function.

Estrogens are produced primarily by the ovaries in women, but they can also be produced in smaller amounts by the adrenal glands and fat cells. In men, estrogens are produced from the conversion of testosterone, the primary male sex hormone, through a process called aromatization.

Estrogen levels vary throughout a woman's life, with higher levels during reproductive years and lower levels after menopause. Estrogen therapy is sometimes used to treat symptoms of menopause, such as hot flashes and vaginal dryness, or to prevent osteoporosis in postmenopausal women. However, estrogen therapy also carries risks, including an increased risk of certain cancers, blood clots, and stroke, so it is typically recommended only for women who have a high risk of these conditions.

The anterior pituitary, also known as the adenohypophysis, is the front portion of the pituitary gland. It is responsible for producing and secreting several important hormones that regulate various bodily functions. These hormones include:

* Growth hormone (GH), which stimulates growth and cell reproduction in bones and other tissues.
* Thyroid-stimulating hormone (TSH), which regulates the production of thyroid hormones by the thyroid gland.
* Adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce cortisol and other steroid hormones.
* Follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which regulate reproductive function in both males and females by controlling the development and release of eggs or sperm.
* Prolactin, which stimulates milk production in pregnant and nursing women.
* Melanocyte-stimulating hormone (MSH), which regulates skin pigmentation and appetite.

The anterior pituitary gland is controlled by the hypothalamus, a small region of the brain located just above it. The hypothalamus produces releasing and inhibiting hormones that regulate the secretion of hormones from the anterior pituitary. These hormones are released into a network of blood vessels called the portal system, which carries them directly to the anterior pituitary gland.

Damage or disease of the anterior pituitary can lead to hormonal imbalances and various medical conditions, such as growth disorders, thyroid dysfunction, adrenal insufficiency, reproductive problems, and diabetes insipidus.

"Wistar rats" are a strain of albino rats that are widely used in laboratory research. They were developed at the Wistar Institute in Philadelphia, USA, and were first introduced in 1906. Wistar rats are outbred, which means that they are genetically diverse and do not have a fixed set of genetic characteristics like inbred strains.

Wistar rats are commonly used as animal models in biomedical research because of their size, ease of handling, and relatively low cost. They are used in a wide range of research areas, including toxicology, pharmacology, nutrition, cancer, cardiovascular disease, and behavioral studies. Wistar rats are also used in safety testing of drugs, medical devices, and other products.

Wistar rats are typically larger than many other rat strains, with males weighing between 500-700 grams and females weighing between 250-350 grams. They have a lifespan of approximately 2-3 years. Wistar rats are also known for their docile and friendly nature, making them easy to handle and work with in the laboratory setting.

Gonadal steroid hormones, also known as gonadal sex steroids, are hormones that are produced and released by the gonads (i.e., ovaries in women and testes in men). These hormones play a critical role in the development and maintenance of secondary sexual characteristics, reproductive function, and overall health.

The three main classes of gonadal steroid hormones are:

1. Androgens: These are male sex hormones that are primarily produced by the testes but also produced in smaller amounts by the ovaries and adrenal glands. The most well-known androgen is testosterone, which plays a key role in the development of male secondary sexual characteristics such as facial hair, deepening of the voice, and increased muscle mass.
2. Estrogens: These are female sex hormones that are primarily produced by the ovaries but also produced in smaller amounts by the adrenal glands. The most well-known estrogen is estradiol, which plays a key role in the development of female secondary sexual characteristics such as breast development and the menstrual cycle.
3. Progestogens: These are hormones that are produced by the ovaries during the second half of the menstrual cycle and play a key role in preparing the uterus for pregnancy. The most well-known progestogen is progesterone, which also plays a role in maintaining pregnancy and regulating the menstrual cycle.

Gonadal steroid hormones can have significant effects on various physiological processes, including bone density, cognitive function, mood, and sexual behavior. Disorders of gonadal steroid hormone production or action can lead to a range of health problems, including infertility, osteoporosis, and sexual dysfunction.

Follicular atresia is a physiological process that occurs in the ovary, where follicles (fluid-filled sacs containing immature eggs or oocytes) undergo degeneration and disappearance. This process begins after the primordial follicle stage and continues throughout a woman's reproductive years. At birth, a female has approximately 1 to 2 million primordial follicles, but only about 400 of these will mature and release an egg during her lifetime. The rest undergo atresia, which is a natural process that helps regulate the number of available eggs and maintain hormonal balance within the body.

The exact mechanisms that trigger follicular atresia are not fully understood, but it is believed to be influenced by various factors such as hormonal imbalances, oxidative stress, and apoptosis (programmed cell death). In some cases, accelerated or excessive follicular atresia can lead to infertility or early menopause.

Sprague-Dawley rats are a strain of albino laboratory rats that are widely used in scientific research. They were first developed by researchers H.H. Sprague and R.C. Dawley in the early 20th century, and have since become one of the most commonly used rat strains in biomedical research due to their relatively large size, ease of handling, and consistent genetic background.

Sprague-Dawley rats are outbred, which means that they are genetically diverse and do not suffer from the same limitations as inbred strains, which can have reduced fertility and increased susceptibility to certain diseases. They are also characterized by their docile nature and low levels of aggression, making them easier to handle and study than some other rat strains.

These rats are used in a wide variety of research areas, including toxicology, pharmacology, nutrition, cancer, and behavioral studies. Because they are genetically diverse, Sprague-Dawley rats can be used to model a range of human diseases and conditions, making them an important tool in the development of new drugs and therapies.

Radioimmunoassay (RIA) is a highly sensitive analytical technique used in clinical and research laboratories to measure concentrations of various substances, such as hormones, vitamins, drugs, or tumor markers, in biological samples like blood, urine, or tissues. The method relies on the specific interaction between an antibody and its corresponding antigen, combined with the use of radioisotopes to quantify the amount of bound antigen.

In a typical RIA procedure, a known quantity of a radiolabeled antigen (also called tracer) is added to a sample containing an unknown concentration of the same unlabeled antigen. The mixture is then incubated with a specific antibody that binds to the antigen. During the incubation period, the antibody forms complexes with both the radiolabeled and unlabeled antigens.

After the incubation, the unbound (free) radiolabeled antigen is separated from the antibody-antigen complexes, usually through a precipitation or separation step involving centrifugation, filtration, or chromatography. The amount of radioactivity in the pellet (containing the antibody-antigen complexes) is then measured using a gamma counter or other suitable radiation detection device.

The concentration of the unlabeled antigen in the sample can be determined by comparing the ratio of bound to free radiolabeled antigen in the sample to a standard curve generated from known concentrations of unlabeled antigen and their corresponding bound/free ratios. The higher the concentration of unlabeled antigen in the sample, the lower the amount of radiolabeled antigen that will bind to the antibody, resulting in a lower bound/free ratio.

Radioimmunoassays offer high sensitivity, specificity, and accuracy, making them valuable tools for detecting and quantifying low levels of various substances in biological samples. However, due to concerns about radiation safety and waste disposal, alternative non-isotopic immunoassay techniques like enzyme-linked immunosorbent assays (ELISAs) have become more popular in recent years.

Lactation is the process by which milk is produced and secreted from the mammary glands of female mammals, including humans, for the nourishment of their young. This physiological function is initiated during pregnancy and continues until it is deliberately stopped or weaned off. The primary purpose of lactation is to provide essential nutrients, antibodies, and other bioactive components that support the growth, development, and immune system of newborns and infants.

The process of lactation involves several hormonal and physiological changes in a woman's body. During pregnancy, the hormones estrogen and progesterone stimulate the growth and development of the mammary glands. After childbirth, the levels of these hormones drop significantly, allowing another hormone called prolactin to take over. Prolactin is responsible for triggering the production of milk in the alveoli, which are tiny sacs within the breast tissue.

Another hormone, oxytocin, plays a crucial role in the release or "let-down" of milk from the alveoli to the nipple during lactation. This reflex is initiated by suckling or thinking about the baby, which sends signals to the brain to release oxytocin. The released oxytocin then binds to receptors in the mammary glands, causing the smooth muscles around the alveoli to contract and push out the milk through the ducts and into the nipple.

Lactation is a complex and highly regulated process that ensures the optimal growth and development of newborns and infants. It provides not only essential nutrients but also various bioactive components, such as immunoglobulins, enzymes, and growth factors, which protect the infant from infections and support their immune system.

In summary, lactation is the physiological process by which milk is produced and secreted from the mammary glands of female mammals for the nourishment of their young. It involves hormonal changes, including the actions of prolactin, oxytocin, estrogen, and progesterone, to regulate the production, storage, and release of milk.

Castration is a surgical procedure to remove the testicles in males or ovaries in females. In males, it is also known as orchiectomy. This procedure results in the inability to produce sex hormones and gametes (sperm in men and eggs in women), and can be done for various reasons such as medical treatment for certain types of cancer, to reduce sexual urges in individuals with criminal tendencies, or as a form of birth control in animals.

"Inbred strains of rats" are genetically identical rodents that have been produced through many generations of brother-sister mating. This results in a high degree of homozygosity, where the genes at any particular locus in the genome are identical in all members of the strain.

Inbred strains of rats are widely used in biomedical research because they provide a consistent and reproducible genetic background for studying various biological phenomena, including the effects of drugs, environmental factors, and genetic mutations on health and disease. Additionally, inbred strains can be used to create genetically modified models of human diseases by introducing specific mutations into their genomes.

Some commonly used inbred strains of rats include the Wistar Kyoto (WKY), Sprague-Dawley (SD), and Fischer 344 (F344) rat strains. Each strain has its own unique genetic characteristics, making them suitable for different types of research.

Equine Gonadotropins are glycoprotein hormones derived from the pituitary gland of horses. They consist of two subunits: a common alpha subunit and a unique beta subunit that determines the biological activity of each hormone. There are two main types of equine gonadotropins: Equine Follicle Stimulating Hormone (eFSH) and Equine Luteinizing Hormone (eLH).

eFSH plays a crucial role in the growth and development of ovarian follicles in females, while eLH stimulates ovulation and the production of sex steroids in both males and females. These hormones are often used in veterinary medicine to induce ovulation and improve fertility in horses, as well as in research to study the physiology and biochemistry of gonadotropins and reproduction. It's important to note that equine gonadotropins have limited application in human reproductive medicine due to potential immunogenic reactions and other safety concerns.

The Fallopian tubes, also known as uterine tubes or oviducts, are a pair of slender tubular structures in the female reproductive system. They play a crucial role in human reproduction by providing a passageway for the egg (ovum) from the ovary to the uterus (womb).

Each Fallopian tube is typically around 7.6 to 10 centimeters long and consists of four parts: the interstitial part, the isthmus, the ampulla, and the infundibulum. The fimbriated end of the infundibulum, which resembles a fringe or frill, surrounds and captures the released egg from the ovary during ovulation.

Fertilization usually occurs in the ampulla when sperm meets the egg after sexual intercourse. Once fertilized, the zygote (fertilized egg) travels through the Fallopian tube toward the uterus for implantation and further development. The cilia lining the inner surface of the Fallopian tubes help propel the egg and the zygote along their journey.

In some cases, abnormalities or blockages in the Fallopian tubes can lead to infertility or ectopic pregnancies, which are pregnancies that develop outside the uterus, typically within the Fallopian tube itself.

3. Diestrus is the period following mating. Diestrus lasts approximately 56 to 60 days in a pregnant female, and 60 to 100 days ... Because the hormonal profile of a pregnant female and a female in diestrus are the same, sometimes a non-pregnant female will ...
Mares may however have multiple FSH waves during a single estrous cycle, and diestrus follicles resulting from a diestrus FSH ... Diestrus, or Luteal, phase: 14-15 days in length, the mare is not sexually receptive to the stallion. The corpus luteum ... High progesterone levels (during diestrus) cause the cervix to close and become toned. Vagina: the portion of the vagina near ... Becomes dry, and closes more tightly, during diestrus. The cycle is controlled by several hormones which regulate the estrous ...
Females that have received estradiol as a mismating shot in diestrus are at risk for more severe disease because estrogen ... 25 percent of females receiving estradiol in diestrus develop pyometra. Pyometra is less common in female cats because ...
Progesterone is highest in the diestrus phase of the estrous cycle. The role of the placenta in progestogen production varies ...
There are four stages of estrous: proestrus, estrus, diestrus, and anestrus. A dog in estrus, also known as being "in heat", ...
Estradiol levels are high on proestrus rats and return to low levels on diestrus rats. The volume of cell bodies within VMN in ... Also, proestrus rats have significantly higher synapse density in VMN than diestrus rats. Moreover, Gamma-aminobutyric acid ... proestrus rats and male rats is larger than diestrus rats. ...
The following day, metestrus, is called early diestrus or diestrus I. During this day, the corpora lutea grow to a maximal ... early diestrus, late diestrus and proestrus/estrus, respectively. Female cattle, also referred to as "heifers" in agriculture, ... early diestrus), 2.25±0.32g (late diestrus), and 1.89±0.31g (proestrus/estrus), respectively. The plasma progesterone ... The proestrus is relatively long at 5 to 9 days, while the estrus may last 4 to 13 days, with a diestrus of 60 days followed by ...
While in dioestrus, the female spends more time with unfamiliar males. In most years in Britain, harvest mice build their first ...
In diestrus, superficial cells are replaced by parabasal and intermediate cells within one to two days of onset. Neutrophils ... A smear made during late estrus to early diestrus may appear similar to one made in early- or mid-proestrus. The final stage of ...
... and diestrus). As a result of estrous cycling, the mammary gland undergoes dynamic changes where cells proliferate and then ...
There is a transient form of acromegaly which can affect females at the diestrus portion of the reproductive cycle. This ...
... and are decreased by fifty percent during di-oestrus. Evidently, the number of gap junctions is influenced by steroid hormone ...
... an increased diestrus period, and a lack of anestrus). Horses also occasionally show anemia and elevated gamma-glutamyl ...
The low levels of pIgR during the diestrus are linked to the downregulating activity of progesterone, which peaks during this ...
... diestrus MeSH G08.520.188.500 - estrus MeSH G08.520.188.500.500 - estrus synchronization MeSH G08.520.188.750 - metestrus MeSH ...
cleavage concealed ovulation conception delamination deuterostome developmental biology diakinesis dioestrus In the mammalian ...
4. Diestrus. This particular cycle only occurs when the female cat has ovulated, which is when she has mated with an unneutered ... In some instances, she doesnt become pregnant, but still has a relatively long diestrus period which can last about 40 days. ...
3. Diestrus is the period following mating. Diestrus lasts approximately 56 to 60 days in a pregnant female, and 60 to 100 days ... Because the hormonal profile of a pregnant female and a female in diestrus are the same, sometimes a non-pregnant female will ...
While Jak2 G−/− mice frequently exhibit persistent diestrus, a number of KO females went through proestrus (Fig. 5A-C). To ... The ovarian weights were also found to be significantly reduced in Jak2 G−/− mice compared with control mice in diestrus (7.68 ... E, Estrus; P, proestrus; M/D, metestrus/diestrus. C, Representative estrous cycles of control, Jak2 G−/− with irregular cycles ... Ovaries were collected at metestrus or diestrus and fixed in 10% buffered formalin phosphate (Fisher Scientific) solution and ...
HK2 was the key regulator of glycogen accumulation during diestrus and pregnancy; hexokinase transcript abundance and enzyme ... and at Day 12 of diestrus and pregnancy. In addition, hexokinase 2 (HK2) activity was assessed using a colorimetric assay. ... activity were significantly higher during diestrus and pregnancy than estrus and anestrus. In addition, despite similar ... Relative transcript abundance of HK2 was highest (P , 0.01) in samples collected during diestrus and pregnancy, with no ...
Gertak Birahi, Laserpunktur, Diestrus, Gnrh, Sel Basofil, Hipofisis Anterior. Subjects:. 600 Technology (Applied sciences) , ... Pengaruh Induksi Laserpunktur Sebagai Metode Gertak Birahi Tikus (Rattus norvegicus) Betina Pada Fase Diestrus Terhadap Kadar ... Betina Pada Fase Diestrus Terhadap Kadar Gnrh Dan Histologi Sel Basofil Hipofisis Anterior. Sarjana thesis, Universitas ... with the result of estrous synchronization from the phase of diestrus to estrus. This examination concludes that laserpuncture ...
Elizabeth GOULD | Cited by 44,005 | of Princeton University, New Jersey (PU) | Read 185 publications | Contact Elizabeth GOULD
Diestrus. The period 10 to 140 days after heat, when the dog is either pregnant or in a resting phase. ...
Diestrus (several cycles in one breeding season). *Pregnancy. *Genetic predisposition. Diabetes is more common in:. *Female ...
Influence of stages anestrous and diestrus in chromatin configuration in germinal vesicle of canine oocytes Leda Maria Costa ...
Pregnancy and diestrus also can predispose to diabetes mellitus. In dogs, but not cats, progesterone leads to release of growth ...
This study aimed to characterize global phospholipid composition of oviduct and uterus during early diestrus in a model of ... Phospholipid Profile and Distribution in the Receptive Oviduct and Uterus During Early Diestrus in Cattle ... as well as progesterone during early diestrus. Oviduct and uterus (4 days after gonadotropin-releasing hormone-induced ...
However, leuprorelin acetate affected estrous cycle and the rat was at diestrus after treatment for two weeks. ... the results of vaginal smear showed that leuprorelin acetate influenced the estrous cycle of the rat which was at diestrus. ...
No prolonged dioestrus was noted in any of the groups.. -Reproductive ability assessment and indices: There were no statistical ...
... diestrus proestrus D P females, n 8; estrus metestrus E M females, n 8, sucrose quinine S Q males, n 8; D P females, n 6; E M ...
Borjesson mentions their diestrus breeding cycle, which produces new generations at twice the rate of wolves; their tremendous ...
It has been shown previously that treatment of mares with oxytocin at certain levels and points in diestrus can maintain the ... Effect of mid-diestrus oxytocin treatment on early pregnancy in the mare. JEVS 125:104776) ... Effect of Administration of Oxytocin During Diestrus on Corpus Luteum Function and Endometrial Oxytocin Receptor Concentration ... by the naturally-occurring prostaglandin release towards the end of diestrus. The hypothesis for this effect is that the ...
Females in the 60 mg/kg group spent more time in diestrus than the vehicle controls. ...
Parity significantly reduced (P , 0.05) GH levels in both estrus and diestrus compared with AMV in both rat strains, indicating ... GH levels in both estrus and diestrus compared with age-matched AMVs in both rat strains. *, P , 0.05; **, P , 0.01; ***, P , ... GH levels in both estrus and diestrus compared with age-matched AMVs in both rat strains. *, P , 0.05; **, P , 0.01; ***, P , ... reduction in circulating levels of GH during estrus and diestrus in both parous strains. Despite the decrease in circulating GH ...
... in diestrus phase of the sexual cycle. The effect of the pineal hormone melatonin (MT) on morphological organization of the ... The study was conducted on 155 female Wistar rats (aged 3 months, body mass--180-200 g), in diestrus phase of the sexual cycle ...
During the breeding season, mares were subjected to OPU in diestrus in the absence of a dominant follicle if at all possible. ...
... and diestrus stages, with provision for extended stays within estrus and diestrus. Equality of transition matrices among ... Tests for extended periods of estrus and diestrus were constructed based on a Markov chain model proposed by Girard and Sager ( ...
Estrus cycle arrest in the metestrus or diestrus phases occurred with the high-dose of 21.5 mg/kg (1.0 times the MRHD based on ... IMPAVIDO caused impaired fertility in female rats and follicular atresia and reversible anestrus/diestrus in dogs at doses ... and mammary gland with morphology consistent with anestrus or diestrus were observed at doses ≥ 1 mg/kg/day (0.2 times the MRHD ...
Accordingly, female rodents in diestrus (low estradiol) are similar to males, in that they exhibit low resting glucocorticoid ...
... and a greater incidence of prolonged diestrus at 100 mg/kg/day [34]. The number of live fetuses and fetal body weight were ...
the expressions remain unaltered in estrus or diestrus. Moreover, the hypothalamic PPO expression had shown increase only ...
3. Late metestrus, early diestrus. 4. Late diestrus, early proestrus. 48. Which one of the following neurotrans¬mitters is ...
The time interval (in days) from the diestrus of an oestrous cycle to the next diestrus was considered as the oestrous cycle ...
Intact female cats should be neutered because the increased progesterone with diestrus makes the management of diabetes more ...
  • hexokinase transcript abundance and enzyme activity were significantly higher during diestrus and pregnancy than estrus and anestrus. (biomedcentral.com)
  • The uterus of cats in diestrus showed lower protein and mRNA expression of ERα and PR compared to proestrus/estrus and anestrus, mainly in the luminal and glandular epithelium and myometrium, different from catalase and SOD1, which showed higher expression in diestrus in relation to other phases of the cycle. (bvsalud.org)
  • GPX1, on the other hand, showed lower uterine gene expression in diestrus compared to proestrus/estrus and anestrus. (bvsalud.org)
  • This is the resting period that lies between diestrus and the next proestrus. (dogsandclogs.com)
  • Cats in proestrus/estrus (N = 6), diestrus, (N = 7), and anestrus (N = 6) were used to evaluate the uterine expression of estrogen alpha (ERα), progesterone (PR), and androgen (AR) receptors and of the antioxidant enzymes superoxide dismutase 1 (SOD1), catalase and glutathione peroxidase 1 (GPX1) by immunohistochemistry and qPCR. (bvsalud.org)
  • 0,05) on the increase of GnRH level of 69,74% and on the total of basophil cells of 45,93% with the result of estrous synchronization from the phase of diestrus to estrus. (ub.ac.id)
  • The rats bearing implants of NE in the median eminence-arcuate nucleus region (MAR) showed irregular estrous cycles or prolonged diestrus and their ovaries had few follicles and atrophic corpora lutea. (karger.com)
  • These include the use of prostaglandins to shorten the luteal phase and cause a resulting shortening of metestrus (diestrus) and of anestrus (Romagnoli et al . (vin.com)
  • Because the hormonal profile of a pregnant female and a female in diestrus are the same, sometimes a non-pregnant female will go through a period of pseudo-pregnancy. (wikipedia.org)
  • Our own interpretation of these results, notwithstanding the author's observation that "In this population of mares, oxytocin administration during mid-diestrus in early pregnancy did not induce a negative effect on pregnancy rate nor a positive effect on progesterone concentration", is that there may be a potential benefit. (equine-reproduction.com)
  • 2023. Effect of mid-diestrus oxytocin treatment on early pregnancy in the mare. (equine-reproduction.com)
  • Unfortunately, mares have the ability to develop follicles, and indeed ovulate follicles, in the face of elevated progestin levels - i.e. during diestrus (the time in between "heat") or pregnancy 3 . (equine-reproduction.com)
  • It has been shown previously that treatment of mares with oxytocin at certain levels and points in diestrus can maintain the corpus luteum beyond the stage where it would normally be lysed (functionally destroyed) by the naturally-occurring prostaglandin release towards the end of diestrus. (equine-reproduction.com)
  • 2012. Effect of Administration of Oxytocin During Diestrus on Corpus Luteum Function and Endometrial Oxytocin Receptor Concentration in Cycling Mares. (equine-reproduction.com)
  • Six light horse mares were confirmed to be in mid-diestrus via teasing, rectal palpation and progesterone testing. (auburn.edu)
  • Following ovariohysterectomy, 13 pairs of ovaries were collected from bitches in anestrus (n = 10) or diestrus (n = 3) and oocytes were harvested by slicing. (tubitak.gov.tr)
  • Intact female cats should be neutered because the increased progesterone with diestrus makes the management of diabetes more difficult. (wedgewoodpharmacy.com)
  • Estrogen levels are low, while progesterone peaks 3 to 4 weeks after the start of diestrus and then declines to basal levels by the end of diestrus. (dog-forums.com)
  • The aims of this study were to investigate the effect of oviductal cells on in vitro maturation (IVM) of canine oocyte in Tissue Culture Medium 199 (TCM-199) or synthetic oviductal fluid (SOF) supplemented with bovine serum albumin (BSA) or fetal calf serum (FCS) and to compare the maturation rates of oocytes from the diestrus and anestrus stages. (tubitak.gov.tr)
  • In conclusion, in the oocytes obtained from bitches in diestrus and anestrus supplemented with FCS or BSA in SOF medium without oviductal cells, more positive effects were seen on canine oocyte maturation than with TCM-199 medium supplemented with same protein sources and oviductal cells. (tubitak.gov.tr)
  • When compared between anestrus and diestrus stages for all parameters (undetermined nuclear material, germinal vesicles, germinal vesicle break down, metaphase I, metaphase II, and degenerated) in different media, the differences were found to be significant statistically in Group IIa (22.9%) and Group IIIb (35.7%) for the germinal vesicle stage (P (tubitak.gov.tr)
  • The dog no more displays signs of sexual desire during diestrus, fans her tail about, and usually no more attempts sexual intercourse in diestrus. (getpetbox.com)
  • The purpose of this study is to identify the influence of laserpuncture induction on GnRH level and on the histology diagram of basophil cell on anterior pituitary on diestrus phase of female rat (Rattus norvegicus). (ub.ac.id)
  • The study was conducted on 155 female Wistar rats (aged 3 months, body mass--180-200 g), in diestrus phase of the sexual cycle. (nih.gov)
  • In some instances, she doesn't become pregnant, but still has a relatively long diestrus period which can last about 40 days. (catster.com)
  • 3. Diestrus is the period following mating. (wikipedia.org)
  • Diestrus lasts approximately 56 to 60 days in a pregnant female, and 60 to 100 days in a non-pregnant female. (wikipedia.org)
  • Diestrus is the stage following estrus and the female is no longer receptive to the male. (dog-forums.com)
  • In the equine endometrium, glycogen content is highest during diestrus, lower during estrus, but almost absent during anestrus. (biomedcentral.com)
  • The hypothesis for this effect is that the exogenous oxytocin inhibits the natural increase in endometrial oxytocin receptor concentration at the end of diestrus that normally leads to oxytocin-induced PGF2α secretion, which in turn would result in luteolysis [1] . (equine-reproduction.com)
  • By doing this, diestrus is prolonged and estrus is suppressed, a phenomenon known as the Whitten effect. (jax.org)
  • The heat or estrus cycle in female dogs is made up of four stages, proestrus, estrus, diestrus and anestrus . (miracleshihtzu.com)
  • The canine estrous cycle , or what we think of as "being in heat," has four phases called proestrus, estrus , diestrus , and anestrus. (vin.com)
  • Diestrus follow s estrus. (vin.com)
  • Doing so will allow the mare to complete at least one - preferably two - regular cycles each consisting of five to seven days of estrus, followed by 14-16 days diestrus ("out of heat") prior to breeding. (equine-reproduction.com)
  • Diestrus is a period of sexual quiescence separating phases of ESTRUS in polyestrous animals. (nih.gov)
  • Diestrus follows estrus and occurs if the female has successfully mated. (theessayworld.com)
  • Miller explained the three stages of a heat cycle - metestrus, diestrus and proestrus. (wylr.net)
  • The diestrus stage is when the female dog's body prepares for pregnancy, and if she is not pregnant, her body will go into anestrus, which is a period of rest before the next cycle begins. (articleinsider.com)
  • Diestrus lasts approximately 56 to 60 days in a pregnant female, and 60 to 100 days in a non-pregnant female. (wikipedia.org)
  • The 3rd stage of the cycle is called Diestrus and lasts 6 - 10 weeks. (pets.ca)
  • After that comes the Diestrus stage which lasts until the next cycle begins. (packlove.com)
  • Diestrus in Golden Retrievers lasts around 60 days. (worldofdogz.com)
  • Diestrus lasts two months if she is pregnant and can last a little longer (2.5 months) if she is not pregnant. (vin.com)
  • Diestrus typically lasts for 56 to 58 days, whether she's pregnant or not. (theessayworld.com)
  • Progesterone levels rise in diestrus to maintain the uterine lining. (qualitycage.com)
  • Diestrus is characterized by high levels of progesterone whether or not she is pregnant. (vin.com)
  • Elevated progesterone levels are necessary to maintain pregnancy, and high progesterone levels are responsible for some of the physical and behavioral changes seen during diestrus, including mammary gland enlargement, increased appetite, and milk production. (vin.com)
  • At the end of diestrus, progesterone levels return to baseline. (vin.com)
  • Also known as the luteal phase, diestrus follows ovulation. (petzooie.com)
  • Diestrus occurs from day five to day 17. (wylr.net)