• In ovariectomized estrogen-primed rats, progesterone as well as 5α-dihydroprogesterone (5α-DHP) are capable of inducing the release of gonadotropins. (elsevierpure.com)
  • This study examined the need of 5α-reduction as a prerequisite for the action of progesterone. (elsevierpure.com)
  • The 5α-reductase inhibitor, N,N-diethyl-4-methyl-3-oxo-4-aza-5α-androstane-17β-carboxamide was injected at a 1 or 2 mg dose/rat 2 h prior to an injection of 0.4 or 0.8 mg progesterone/kg body weight at 0900 h to immature ovariectomized, estrogen-primed rats and serum was analyzed for LH and FSH at 1500 h. (elsevierpure.com)
  • Pituitary and hypothalamic 5α-reductase activity was measured at the time of progesterone administration and at the time of the surge by incubating tissue homogenates with [ 3 H]progesterone. (elsevierpure.com)
  • Substrate, ([ 3 H]progesterone) and product ([ 3 H]5α-DHP), were separated by reverse phase HPLC. (elsevierpure.com)
  • However, both pituitary and hypothalamic 5α-reductase was blocked at the time of progesterone administration. (elsevierpure.com)
  • No effect was seen by acute administration of the 5α-reductase inhibitor upon either the 0.4 or 0.8 mg progesterone/kg-induced release of LH and FSH. (elsevierpure.com)
  • There was, however, a specific, significant inhibition of progesterone-induced FSH but not LH release when the 5α-reductase inhibition was sustained throughout the afternoon of the gonadotropin surge. (elsevierpure.com)
  • These results indicate a biologically significant role for the irreversible 5α-reduction of progesterone in the modulation of the release of FSH. (elsevierpure.com)
  • The recent cloning and sequencing of a gene coding for a membranous progesterone receptor [ 5 ] in African clawed frog ( Xenopus laevis ) brought evidence for the existence of both intracellular and membrane progestin receptors [ 6 ]. (biomedcentral.com)
  • Our cancer studies have expanded to include oesophageal cancer with emphasis on oestrogen receptor expression and function in this malignancy. (nottingham.ac.uk)
  • PSSOC was relevant to avoid surgery in 2 patients (5%) with indeterminate strictures, allowing to rule out malignancy and treat the lithiasis. (bvsalud.org)
  • subtypes alpha, beta and gamma), was recently described in vertebrates and implicated in the progestin-initiated induction of oocyte maturation in fish. (biomedcentral.com)
  • Putnam-Roberts, C , Brann, DW & Mahesh, VB 1992, ' Role of 5α-reduction in progesterone's ability to release FSH in estrogen-primed ovariectomized rats ', Journal of Steroid Biochemistry and Molecular Biology , vol. 42, no. 8, pp. 875-882. (elsevierpure.com)
  • The time course of progesterone effects on anterior pituitary nuclear estrogen receptors will be studied at 1, 2, 3, 4, 8 and 12 hrs after the progesterone injection in vivo and the effects of progesterone metabolites on estrogen receptor dynamics will be evaluated. (elsevierpure.com)
  • The estrogen receptor α (ERα) is a target of intense pharmacological intervention and toxicological biomonitoring. (nih.gov)
  • 9. Induction of aromatase (CYP19) expression in breast cancer cells through a nongenomic action of estrogen receptor alpha. (nih.gov)
  • In parallel, we have also observed, in the same hypothalamic nuclei, a significant reduction of the membrane estrogen receptor GPER1 expression. (bvsalud.org)
  • Suppression of Delta(5)-androstenediol-induced androgen receptor transactivation by selective steroids in human prostate cancer cells. (lookformedical.com)
  • Our earlier report suggested that androst-5-ene-3beta,7beta-diol (Delta(5)-androstenediol or Adiol) is a natural hormone with androgenic activity and that two potent antiandrogens, hydroxyflutamide (Eulexin) and bicalutamide (Casodex), fail to block completely the Adiol-induced androgen receptor (AR) transactivation in prostate cancer cells. (lookformedical.com)
  • Analyzing the consequences of bisphenol exposure on EAE will help to better understand the role of both xenoestrogens and endogenous estrogens on the sexually dimorphic characteristics of MS. (bvsalud.org)
  • 20a-Dihydroprogesterone (20a-DHP), also known as 20a-hydroxyprogesterone (20a-OHP), is a naturally occurring, endogenous progestogen. (healthmatters.io)
  • 3a-Dihydroprogesterone (3a-DHP), also known as 3a-hydroxyprogesterone, is an endogenous neurosteroid. (healthmatters.io)
  • 4-Methoxyestradiol (4-ME2) is an endogenous, naturally occurring methoxylated catechol estrogen and metabolite of estradiol that is formed by catechol O-methyltransferase via the intermediate 4-hydroxyestradiol. (healthmatters.io)
  • and 3 Beta, 5 Alpha-reduced metabolites of progesterone on FSH and LH secretion. (elsevierpure.com)
  • The requirement for 5 Alpha-reduction of progesterone for FSH release will be tested by using a 5 Alpha-reductase inhibitor. (elsevierpure.com)
  • The effect of progesterone metabolites on hypothalamic LHRH secretion will be evaluated by measuring medial basal hypothalamic, preoptic area, and plasma LHRH levels along with serum LH and FSH levels at 15 min intervals after injecting the progestin in estrogen-primed castrated rats. (elsevierpure.com)
  • The specificity of the effect of progesterone treatment of the nuclei or cytosol in depleting nuclear estradiol receptors in vitro will be studied by examining the effects of cholesterol, corticosterone and 5 Alpha-dihydrotestosterone. (elsevierpure.com)
  • Whether transcription and/or protein synthesis is involved in the action of progesterone in the reduction of occupied nuclear estrogen receptors will be determined by using actinomycin-D and cycloheximide. (elsevierpure.com)
  • Experiments will be done to determine the interactive effects of progesterone on estrogen receptors and estrogens on progesterone receptors and to determine if progesterone modulates its own receptors. (elsevierpure.com)
  • In these studies, cytoplasmic and nuclear estradiol and progesterone receptors will be measured after treatment of castrated rats with various estrogen and progesterone regimens. (elsevierpure.com)
  • Emphasis is given to preclinical studies that examined genomic and rapid membrane effects of estrogen, progesterone, glucocorticoids, and GABAergic neurosteroids for their effects on alcohol drinking and models of relapse. (nih.gov)
  • 17. The anti-aromatase effect of progesterone and of its natural metabolites 20alpha- and 5alpha-dihydroprogesterone in the MCF-7aro breast cancer cell line. (nih.gov)
  • The selective release of FSH by 5 Alpha-dihydroprogesterone and selective release of LH by 3 Alpha-hydroxy-5 Alpha-pregnant-20-one will be confirmed in the 21-day-old rat injected with pregnant mare's serum gonadotropin. (elsevierpure.com)
  • 2. A positive feedback pathway of estrogen biosynthesis in breast cancer cells is contained by resveratrol. (nih.gov)
  • 4-5,10,12 As a result, it should be considered that alcohol consumption can influence the endocrine system and the reciprocal interaction between the stress and reproductive axes and that gonadal and stress steroid hormones can influence alcohol drinking and addiction-related behaviors. (nih.gov)
  • The 2-Methoxy Estrogens are considered to be protective. (healthmatters.io)
  • Healthy Phase II metabolism methylates 2-hydroxy (2-OH) estrogens to the more cancer-protective 2-methoxy (2-MeO) forms, and neutralizes the potentially carcinogenic 4-OH estrogens to their 4-MeO forms. (healthmatters.io)
  • DHEA appears to mediate its protective effect by a mechanism that blocks the toxin-induced production of pathophysiological levels of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1. (lookformedical.com)
  • however, the AED effect was independent of TNF-alpha suppression, both in vivo and in vitro. (lookformedical.com)
  • Kaempferol (3,4′,5,7-tetrahydroxyflavone) is a natural flavonol , a type of flavonoid , found in a variety of plants and plant-derived foods including kale , beans , tea , spinach , and broccoli . (thcscience.wiki)
  • 5. Cyclooxygenase-2 directly regulates gene expression of P450 Cyp19 aromatase promoter regions pII, pI.3 and pI.7 and estradiol production in human breast tumor cells. (nih.gov)
  • and no. 10, 3beta-methylcarbonate-androst-5-ene-7,17-dione] that have no androgenic activity and could also block the Adiol-induced AR transactivation in prostate cancer PC-3 cells. (lookformedical.com)