Vasopressins: Antidiuretic hormones released by the NEUROHYPOPHYSIS of all vertebrates (structure varies with species) to regulate water balance and OSMOLARITY. In general, vasopressin is a nonapeptide consisting of a six-amino-acid ring with a cysteine 1 to cysteine 6 disulfide bridge or an octapeptide containing a CYSTINE. All mammals have arginine vasopressin except the pig with a lysine at position 8. Vasopressin, a vasoconstrictor, acts on the KIDNEY COLLECTING DUCTS to increase water reabsorption, increase blood volume and blood pressure.Arginine Vasopressin: The predominant form of mammalian antidiuretic hormone. It is a nonapeptide containing an ARGININE at residue 8 and two disulfide-linked cysteines at residues of 1 and 6. Arg-vasopressin is used to treat DIABETES INSIPIDUS or to improve vasomotor tone and BLOOD PRESSURE.Receptors, Vasopressin: Specific molecular sites or proteins on or in cells to which VASOPRESSINS bind or interact in order to modify the function of the cells. Two types of vasopressin receptor exist, the V1 receptor in the vascular smooth muscle and the V2 receptor in the kidneys. The V1 receptor can be subdivided into V1a and V1b (formerly V3) receptors.Deamino Arginine Vasopressin: A synthetic analog of the pituitary hormone, ARGININE VASOPRESSIN. Its action is mediated by the VASOPRESSIN receptor V2. It has prolonged antidiuretic activity, but little pressor effects. It also modulates levels of circulating FACTOR VIII and VON WILLEBRAND FACTOR.Oxytocin: A nonapeptide hormone released from the neurohypophysis (PITUITARY GLAND, POSTERIOR). It differs from VASOPRESSIN by two amino acids at residues 3 and 8. Oxytocin acts on SMOOTH MUSCLE CELLS, such as causing UTERINE CONTRACTIONS and MILK EJECTION.Rats, Brattleboro: A mutant strain of Rattus norvegicus used in research on renal function and hypertension and as a disease model for diabetes insipidus.Lypressin: The porcine antidiuretic hormone (VASOPRESSINS). It is a cyclic nonapeptide that differs from ARG-VASOPRESSIN by one amino acid, containing a LYSINE at residue 8 instead of an ARGININE. Lys-vasopressin is used to treat DIABETES INSIPIDUS or to improve vasomotor tone and BLOOD PRESSURE.Neurophysins: Carrier proteins for OXYTOCIN and VASOPRESSIN. They are polypeptides of about 10-kDa, synthesized in the HYPOTHALAMUS. Neurophysin I is associated with oxytocin and neurophysin II is associated with vasopressin in their respective precursors and during transportation down the axons to the neurohypophysis (PITUITARY GLAND, POSTERIOR).Renal Agents: Drugs used for their effects on the kidneys' regulation of body fluid composition and volume. The most commonly used are the diuretics. Also included are drugs used for their antidiuretic and uricosuric actions, for their effects on the kidneys' clearance of other drugs, and for diagnosis of renal function.Diabetes Insipidus: A disease that is characterized by frequent urination, excretion of large amounts of dilute URINE, and excessive THIRST. Etiologies of diabetes insipidus include deficiency of antidiuretic hormone (also known as ADH or VASOPRESSIN) secreted by the NEUROHYPOPHYSIS, impaired KIDNEY response to ADH, and impaired hypothalamic regulation of thirst.Pituitary Gland, Posterior: Neural tissue of the pituitary gland, also known as the neurohypophysis. It consists of the distal AXONS of neurons that produce VASOPRESSIN and OXYTOCIN in the SUPRAOPTIC NUCLEUS and the PARAVENTRICULAR NUCLEUS. These axons travel down through the MEDIAN EMINENCE, the hypothalamic infundibulum of the PITUITARY STALK, to the posterior lobe of the pituitary gland.Vasotocin: A nonapeptide that contains the ring of OXYTOCIN and the side chain of ARG-VASOPRESSIN with the latter determining the specific recognition of hormone receptors. Vasotocin is the non-mammalian vasopressin-like hormone or antidiuretic hormone regulating water and salt metabolism.Antidiuretic Agents: Agents that reduce the excretion of URINE, most notably the octapeptide VASOPRESSINS.Supraoptic Nucleus: Hypothalamic nucleus overlying the beginning of the OPTIC TRACT.Aquaporin 2: Aquaporin 2 is a water-specific channel protein that is expressed in KIDNEY COLLECTING DUCTS. The translocation of aquaporin 2 to the apical PLASMA MEMBRANE is regulated by VASOPRESSIN, and MUTATIONS in AQP2 have been implicated in a variety of kidney disorders including DIABETES INSIPIDUS.Pituitary Hormones, Posterior: Hormones released from the neurohypophysis (PITUITARY GLAND, POSTERIOR). They include a number of peptides which are formed in the NEURONS in the HYPOTHALAMUS, bound to NEUROPHYSINS, and stored in the nerve terminals in the posterior pituitary. Upon stimulation, these peptides are released into the hypophysial portal vessel blood.Kidney Tubules, Collecting: Straight tubes commencing in the radiate part of the kidney cortex where they receive the curved ends of the distal convoluted tubules. In the medulla the collecting tubules of each pyramid converge to join a central tube (duct of Bellini) which opens on the summit of the papilla.Water Deprivation: The withholding of water in a structured experimental situation.Diuresis: An increase in the excretion of URINE. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Water-Electrolyte Balance: The balance of fluid in the BODY FLUID COMPARTMENTS; total BODY WATER; BLOOD VOLUME; EXTRACELLULAR SPACE; INTRACELLULAR SPACE, maintained by processes in the body that regulate the intake and excretion of WATER and ELECTROLYTES, particularly SODIUM and POTASSIUM.Receptors, Oxytocin: Cell surface proteins that bind oxytocin with high affinity and trigger intracellular changes which influence the behavior of cells. Oxytocin receptors in the uterus and the mammary glands mediate the hormone's stimulation of contraction and milk ejection. The presence of oxytocin and oxytocin receptors in neurons of the brain probably reflects an additional role as a neurotransmitter.Aquaporin 6: Aquaporin 6 is an aquaglyceroporin that is found primarily in KIDNEY COLLECTING DUCTS. AQP6 protein functions as an anion-selective channel.Osmolar Concentration: The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.Hyponatremia: Deficiency of sodium in the blood; salt depletion. (Dorland, 27th ed)Inappropriate ADH Syndrome: A condition of HYPONATREMIA and renal salt loss attributed to overexpansion of BODY FLUIDS resulting from sustained release of ANTIDIURETIC HORMONES which stimulates renal resorption of water. It is characterized by normal KIDNEY function, high urine OSMOLALITY, low serum osmolality, and neurological dysfunction. Etiologies include ADH-producing neoplasms, injuries or diseases involving the HYPOTHALAMUS, the PITUITARY GLAND, and the LUNG. This syndrome can also be drug-induced.Kidney Medulla: The internal portion of the kidney, consisting of striated conical masses, the renal pyramids, whose bases are adjacent to the cortex and whose apices form prominent papillae projecting into the lumen of the minor calyces.Kidney Concentrating Ability: The ability of the kidney to excrete in the urine high concentrations of solutes from the blood plasma.Diabetes Insipidus, Nephrogenic: A genetic or acquired polyuric disorder characterized by persistent hypotonic urine and HYPOKALEMIA. This condition is due to renal tubular insensitivity to VASOPRESSIN and failure to reduce urine volume. It may be the result of mutations of genes encoding VASOPRESSIN RECEPTORS or AQUAPORIN-2; KIDNEY DISEASES; adverse drug effects; or complications from PREGNANCY.Rats, Inbred Strains: 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.Paraventricular Hypothalamic Nucleus: Nucleus in the anterior part of the HYPOTHALAMUS.Thirst: A drive stemming from a physiological need for WATER.Vasoconstrictor Agents: Drugs used to cause constriction of the blood vessels.Saline Solution, Hypertonic: Hypertonic sodium chloride solution. A solution having an osmotic pressure greater than that of physiologic salt solution (0.9 g NaCl in 100 ml purified water).Kidney: Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.Receptors, Angiotensin: Cell surface proteins that bind ANGIOTENSINS and trigger intracellular changes influencing the behavior of cells.Polyuria: Urination of a large volume of urine with an increase in urinary frequency, commonly seen in diabetes (DIABETES MELLITUS; DIABETES INSIPIDUS).Hypothalamus: Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.Aquaporins: A class of porins that allow the passage of WATER and other small molecules across CELL MEMBRANES.Dehydration: The condition that results from excessive loss of water from a living organism.Sodium: A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.Corticotropin-Releasing Hormone: A peptide of about 41 amino acids that stimulates the release of ADRENOCORTICOTROPIC HORMONE. CRH is synthesized by neurons in the PARAVENTRICULAR NUCLEUS of the HYPOTHALAMUS. After being released into the pituitary portal circulation, CRH stimulates the release of ACTH from the PITUITARY GLAND. CRH can also be synthesized in other tissues, such as PLACENTA; ADRENAL MEDULLA; and TESTIS.Benzazepines: Compounds with BENZENE fused to AZEPINES.Urine: Liquid by-product of excretion produced in the kidneys, temporarily stored in the bladder until discharge through the URETHRA.Angiotensin II: An octapeptide that is a potent but labile vasoconstrictor. It is produced from angiotensin I after the removal of two amino acids at the C-terminal by ANGIOTENSIN CONVERTING ENZYME. The amino acid in position 5 varies in different species. To block VASOCONSTRICTION and HYPERTENSION effect of angiotensin II, patients are often treated with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.Injections, Intraventricular: Injections into the cerebral ventricles.Ornipressin: A synthetic analog of vasopressin with ORNITHINE substitution at residue 8 of the cyclic nonapeptide. It is used as a local vasoconstrictor and hemostatic.Hypothalamo-Hypophyseal System: A collection of NEURONS, tracts of NERVE FIBERS, endocrine tissue, and blood vessels in the HYPOTHALAMUS and the PITUITARY GLAND. This hypothalamo-hypophyseal portal circulation provides the mechanism for hypothalamic neuroendocrine (HYPOTHALAMIC HORMONES) regulation of pituitary function and the release of various PITUITARY HORMONES into the systemic circulation to maintain HOMEOSTASIS.Rats, Sprague-Dawley: 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.Adrenocorticotropic Hormone: An anterior pituitary hormone that stimulates the ADRENAL CORTEX and its production of CORTICOSTEROIDS. ACTH is a 39-amino acid polypeptide of which the N-terminal 24-amino acid segment is identical in all species and contains the adrenocorticotrophic activity. Upon further tissue-specific processing, ACTH can yield ALPHA-MSH and corticotrophin-like intermediate lobe peptide (CLIP).Hormone Antagonists: Chemical substances which inhibit the function of the endocrine glands, the biosynthesis of their secreted hormones, or the action of hormones upon their specific sites.Epinephrine: The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS.Hypothalamus, Anterior: The front portion of the HYPOTHALAMUS separated into the preoptic region and the supraoptic region. The preoptic region is made up of the periventricular GRAY MATTER of the rostral portion of the THIRD VENTRICLE and contains the preoptic ventricular nucleus and the medial preoptic nucleus. The supraoptic region contains the PARAVENTRICULAR HYPOTHALAMIC NUCLEUS, the SUPRAOPTIC NUCLEUS, the ANTERIOR HYPOTHALAMIC NUCLEUS, and the SUPRACHIASMATIC NUCLEUS.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Osmosis: Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane.Cyclic AMP: An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.Norepinephrine: Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.Drinking: The consumption of liquids.Spiro Compounds: A group of compounds consisting in part of two rings sharing one atom (usually a carbon) in common.Diabetes Insipidus, Neurogenic: A genetic or acquired polyuric disorder caused by a deficiency of VASOPRESSINS secreted by the NEUROHYPOPHYSIS. Clinical signs include the excretion of large volumes of dilute URINE; HYPERNATREMIA; THIRST; and polydipsia. Etiologies include HEAD TRAUMA; surgeries and diseases involving the HYPOTHALAMUS and the PITUITARY GLAND. This disorder may also be caused by mutations of genes such as ARVP encoding vasopressin and its corresponding neurophysin (NEUROPHYSINS).Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Pressoreceptors: Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.Hypernatremia: Excessive amount of sodium in the blood. (Dorland, 27th ed)Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Neurosecretion: The production and release of substances such as NEUROTRANSMITTERS or HORMONES from nerve cells.PyrrolidinesWater: A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Bombesin: A tetradecapeptide originally obtained from the skins of toads Bombina bombina and B. variegata. It is also an endogenous neurotransmitter in many animals including mammals. Bombesin affects vascular and other smooth muscle, gastric secretion, and renal circulation and function.Phenylephrine: An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent.Natriuresis: Sodium excretion by URINATION.Saralasin: An octapeptide analog of angiotensin II (bovine) with amino acids 1 and 8 replaced with sarcosine and alanine, respectively. It is a highly specific competitive inhibitor of angiotensin II that is used in the diagnosis of HYPERTENSION.Pair Bond: In animals, the social relationship established between a male and female for reproduction. It may include raising of young.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Glucagon: A 29-amino acid pancreatic peptide derived from proglucagon which is also the precursor of intestinal GLUCAGON-LIKE PEPTIDES. Glucagon is secreted by PANCREATIC ALPHA CELLS and plays an important role in regulation of BLOOD GLUCOSE concentration, ketone metabolism, and several other biochemical and physiological processes. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p1511)Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Neurosecretory Systems: A system of NEURONS that has the specialized function to produce and secrete HORMONES, and that constitutes, in whole or in part, an ENDOCRINE SYSTEM or organ.Body Water: Fluids composed mainly of water found within the body.Inositol Phosphates: Phosphoric acid esters of inositol. They include mono- and polyphosphoric acid esters, with the exception of inositol hexaphosphate which is PHYTIC ACID.Kidney Tubules: Long convoluted tubules in the nephrons. They collect filtrate from blood passing through the KIDNEY GLOMERULUS and process this filtrate into URINE. Each renal tubule consists of a BOWMAN CAPSULE; PROXIMAL KIDNEY TUBULE; LOOP OF HENLE; DISTAL KIDNEY TUBULE; and KIDNEY COLLECTING DUCT leading to the central cavity of the kidney (KIDNEY PELVIS) that connects to the URETER.Adenylate Cyclase: An enzyme of the lyase class that catalyzes the formation of CYCLIC AMP and pyrophosphate from ATP. EC 4.6.1.1.Bufo marinus: A species of the true toads, Bufonidae, becoming fairly common in the southern United States and almost pantropical. The secretions from the skin glands of this species are very toxic to animals.Renin: A highly specific (Leu-Leu) endopeptidase that generates ANGIOTENSIN I from its precursor ANGIOTENSINOGEN, leading to a cascade of reactions which elevate BLOOD PRESSURE and increase sodium retention by the kidney in the RENIN-ANGIOTENSIN SYSTEM. The enzyme was formerly listed as EC 3.4.99.19.Phosphorylase a: The active form of GLYCOGEN PHOSPHORYLASE that is derived from the phosphorylation of PHOSPHORYLASE B. Phosphorylase a is deactivated via hydrolysis of phosphoserine by PHOSPHORYLASE PHOSPHATASE to form PHOSPHORYLASE B.Vascular Resistance: The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.Atrial Natriuretic Factor: A potent natriuretic and vasodilatory peptide or mixture of different-sized low molecular weight PEPTIDES derived from a common precursor and secreted mainly by the HEART ATRIUM. All these peptides share a sequence of about 20 AMINO ACIDS.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Aldosterone: A hormone secreted by the ADRENAL CORTEX that regulates electrolyte and water balance by increasing the renal retention of sodium and the excretion of potassium.Stimulation, Chemical: The increase in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.Pituitary-Adrenal System: The interactions between the anterior pituitary and adrenal glands, in which corticotropin (ACTH) stimulates the adrenal cortex and adrenal cortical hormones suppress the production of corticotropin by the anterior pituitary.Shock, Septic: Sepsis associated with HYPOTENSION or hypoperfusion despite adequate fluid resuscitation. Perfusion abnormalities may include, but are not limited to LACTIC ACIDOSIS; OLIGURIA; or acute alteration in mental status.Median Eminence: Raised area at the infundibular region of the HYPOTHALAMUS at the floor of the BRAIN, ventral to the THIRD VENTRICLE and adjacent to the ARCUATE NUCLEUS OF HYPOTHALAMUS. It contains the terminals of hypothalamic neurons and the capillary network of hypophyseal portal system, thus serving as a neuroendocrine link between the brain and the PITUITARY GLAND.Phosphorylases: A class of glucosyltransferases that catalyzes the degradation of storage polysaccharides, such as glucose polymers, by phosphorolysis in animals (GLYCOGEN PHOSPHORYLASE) and in plants (STARCH PHOSPHORYLASE).

Vasopressin stimulation of acetate incorporation into lipids in a dimethylbenz(a)anthracene-induced rat mammary tumor cell line. (1/2313)

In a preliminary report we described the effects of rat prolactin on the incorporation of [14C]acetate into lipids by a cell line from a dimethylbenz(a)anthracene-induced rat mammary tumor. The characteristics of the response to prolactin were very similar to those described for the normal rat mammary gland; namely, insulin was required for full expression of the response, maximal activity was not seen until 36 hr after the addition of the hormones, and growth hormone was able to elicit the same response. However, we were unable to detect binding of 125I-labeled prolactin to these cells, and furthermore, other more purified prolactin preparations were inactive. Upon further investigation we discovered that the activity resided in a low-molecular-weight fraction of the rat prolactin B-1 preparation and was probably either vasopressin or oxytocin or both. These data suggest the possibility that vasopressin may play a role in rodent mammary tumorigenesis.  (+info)

Evidence for a vasopressin system in the rat heart. (2/2313)

Traditionally, a hypothalamo-neurohypophysial system is thought to be the exclusive source of arginine vasopressin (AVP), a potent antidiuretic, vasoconstricting, and growth-stimulating neuropeptide. We have identified de novo synthesis of AVP in the heart as well as release of the hormone into the cardiac effluents. Specifically, molecular cloning of sequence tags amplified from isolated, buffer-perfused, and pressure-overloaded rat hearts allowed the detection of cardiac AVP mRNA. Subsequent experiments revealed a prominent induction of AVP mRNA (peak at 120 minutes, 59-fold, P<0. 01 versus baseline) and peptide (peak at 120 minutes, 11-fold, P<0. 01 versus baseline) in these isolated hearts. Newly induced vasopressin peptide was localized most prominently to endothelial cells and vascular smooth muscle cells of arterioles and perivascular tissue using immunohistochemistry. In addition to pressure overload, nitric oxide (NO) participated in these alterations, because inhibition of NO synthase by Nomega-nitro-L-arginine methyl ester markedly depressed cardiac AVP mRNA and peptide induction. Immediate cardiac effects related to cardiac AVP induction in isolated, perfused, pressure-overloaded hearts appeared to be coronary vasoconstriction and impaired relaxation. These functional changes were observed in parallel with AVP induction and largely prevented by addition of a V1 receptor blocker (10(-8) mol/L [deamino-Pen1, O-Me-Tyr2, Arg8]-vasopressin) to the perfusion buffer. Even more interesting, pressure-overloaded, isolated hearts released the peptide into the coronary effluents, offering the potential for systemic actions of AVP from cardiac origin. We conclude that the heart, stressed by acute pressure overload or NO, expresses vasopressin in concentrations sufficient to cause local and potentially systemic effects.  (+info)

Central peptidergic neurons are hyperactive during collateral sprouting and inhibition of activity suppresses sprouting. (3/2313)

Little is known regarding the effect of chronic changes in neuronal activity on the extent of collateral sprouting by identified CNS neurons. We have investigated the relationship between activity and sprouting in oxytocin (OT) and vasopressin (VP) neurons of the hypothalamic magnocellular neurosecretory system (MNS). Uninjured MNS neurons undergo a robust collateral-sprouting response that restores the axon population of the neural lobe (NL) after a lesion of the contralateral MNS (). Simultaneously, lesioned rats develop chronic urinary hyperosmolality indicative of heightened neurosecretory activity. We therefore tested the hypothesis that sprouting MNS neurons are hyperactive by measuring changes in cell and nuclear diameters, OT and VP mRNA pools, and axonal cytochrome oxidase activity (COX). Each of these measures was significantly elevated during the period of most rapid axonal growth between 1 and 4 weeks after the lesion, confirming that both OT and VP neurons are hyperactive while undergoing collateral sprouting. In a second study the hypothesis that chronic inhibition of neuronal activity would interfere with the sprouting response was tested. Chronic hyponatremia (CH) was induced 3 d before the hypothalamic lesion and sustained for 4 weeks to suppress neurosecretory activity. CH abolished the lesion-induced increases in OT and VP mRNA pools and virtually eliminated measurable COX activity in MNS terminals. Counts of the total number of axon profiles in the NL revealed that CH also prevented axonal sprouting from occurring. These results are consistent with the hypothesis that increased neuronal activity is required for denervation-induced collateral sprouting to occur in the MNS.  (+info)

Why is the retention of gonadotrophin secretion common in children with panhypopituitarism due to septo-optic dysplasia? (4/2313)

Septo-optic dysplasia (De Morsier syndrome) is a developmental anomaly of mid-line brain structures and includes optic nerve hypoplasia, absence of the septum pellucidum and hypothalamo-pituitary abnormalities. We describe seven patients (four female, three male) who had at least two out of the three features necessary for the diagnosis of septo-optic dysplasia. Four patients had hypopituitarism and yet normal gonadotrophin secretion: one of these also had anti-diuretic hormone insufficiency; three had isolated GH deficiency and yet had premature puberty, with the onset of puberty at least a year earlier than would have been expected for their bone age. In any progressive and evolving anterior pituitary lesion it is extremely unusual to lose corticotrophin-releasing hormone/ACTH and TRH/TSH secretion and yet to retain gonadotrophin secretion. GnRH neurons develop in the nasal mucosa and migrate to the hypothalamus in early fetal life. We hypothesise that the arrival of GnRH neurons in the hypothalamus after the development of a midline hypothalamic defect may explain these phenomena. Progress in spontaneous/premature puberty in children with De Morsier syndrome may have important implications for management. The combination of GH deficiency and premature puberty may allow an apparently normal growth rate but with an inappropriately advanced bone age resulting in impaired final stature. GnRH analogues may be a therapeutic option. In conclusion, some patients with De Morsier syndrome appear to retain the ability to secrete gonadotrophins in the face of loss of other hypothalamic releasing factors. The migration of GnRH neurons after the development of the midline defect may be an explanation.  (+info)

Comparison of two aquaretic drugs (niravoline and OPC-31260) in cirrhotic rats with ascites and water retention. (5/2313)

kappa-Opioid receptor agonists (niravoline) or nonpeptide antidiuretic hormone (ADH) V2 receptor antagonists (OPC-31260) possess aquaretic activity in cirrhosis; however, there is no information concerning the effects induced by the chronic administration of these drugs under this condition. To compare the renal and hormonal effects induced by the long-term oral administration of niravoline, OPC-31260, or vehicle, urine volume, urinary osmolality, sodium excretion, and urinary excretion of aldosterone (ALD) and ADH were measured in basal conditions and for 10 days after the daily oral administration of niravoline, OPC-31260, or vehicle to cirrhotic rats with ascites and water retention. Creatinine clearance, serum osmolality, ADH mRNA expression, and systemic hemodynamics were also measured at the end of the study. Niravoline increased water excretion, peripheral resistance, serum osmolality, and sodium excretion and reduced creatinine clearance, ALD and ADH excretion, and mRNA expression of ADH. OPC-31260 also increased water metabolism and sodium excretion and reduced urinary ALD, although the aquaretic effect was only evident during the first 2 days, and no effects on serum osmolality, renal filtration, and systemic hemodynamics were observed. Therefore, both agents have aquaretic efficacy, but the beneficial therapeutic effects of the long-term oral administration of niravoline are more consistent than those of OPC-31260 in cirrhotic rats with ascites and water retention.  (+info)

Stimulus-dependent translocation of kappa opioid receptors to the plasma membrane. (6/2313)

We examined the cellular and subcellular distribution of the cloned kappa opioid receptor (KOR1) and its trafficking to the presynaptic plasma membrane in vasopressin magnocellular neurosecretory neurons. We used immunohistochemistry to show that KOR1 immunoreactivity (IR) colocalized with vasopressin-containing cell bodies, axons, and axon terminals within the posterior pituitary. Ultrastructural analysis revealed that a major fraction of KOR1-IR was associated with the membrane of peptide-containing large secretory vesicles. KOR1-IR was rarely associated with the plasma membrane in unstimulated nerve terminals within the posterior pituitary. A physiological stimulus (salt-loading) that elicits vasopressin release also caused KOR1-IR to translocate from these vesicles to the plasma membrane. After stimulation, there was a significant decrease in KOR1-IR associated with peptide-containing vesicles and a significant increase in KOR1-IR associated with the plasma membrane. This stimulus-dependent translocation of receptors to the presynaptic plasma membrane provides a novel mechanism for regulation of transmitter release.  (+info)

Resistance to hepatic action of vasopressin in genetically obese (ob/ob) mice. (7/2313)

1. Fatty acid synthesis, measured in the perfused liver of genetically obese (ob/ob) mice with 3H2O or [14C]actate, did not show the inhibition by [8-arginine]vasopressin (antidiuretic hormone) that is observed in livers from normal mice. 2. Hepatic glycogen breakdown in obese mice was stimuulated by vasopressin, but not as extensively as in lean mice. 3. If obese mice received a restricted amount of food, then fatty acid synthesis still did not respond to vasopressin, but glycogen breakdown was fully stimulated. 4. Cholesterol synthesis was not inhibited by vasopressin in livers from obese mice. 5. Vasopressin inhibited fatty acid synthesis in intact lean mice, but not in obese animals. 6. These results suggest that genetic obesity could be due to an inborn error within the mechanisms (other than adenylate cyclase) which mediate responses to extracellular effectors.  (+info)

Evidence for calcium inactivation during hormone release in the rat neurohypophysis. (8/2313)

1. A study has been made of the relationship between 45Ca uptake into and hormone release from isolated rat neurohypophyses incubated in vitro. 2. Hormone secretion is triggered by high-K (56 mM) but long exposure to the stimulus does not generate a maintained release of hormone. 3. When hormone release began to wane, addition of Ba of La increased hormone output which suggests that the decline in output did not result from depletion of the neurosecretory granules at the nerve terminals. 4. 45Ca uptake is enhanced in the presence of high-K concentration, but the initial high rate declines during long exposure to the potassium stimulus with a time constant similar to that of the decline in hormone release. 5. After a period of incubation in a K-rich, calcium-free medium, addition of calcium to the medium induced hormone release. The magnitude of this release was dependent on the time of exposure to excess potassium. 6. After inactivation of secretion, mobilization of internal calcium by means of a calcium ionophore increased hormone release.  (+info)

  • Recent research from Dr. Dan Krawczyk's lab at the Center for BrainHealth explored whether administering two chemically similar hormones known to affect social cognition - oxytocin and vasopressin - would influence the perception of trustworthiness and/or social dominance. (news-medical.net)
  • Background: Studies in experimental animals show that endogenous Arg- vasopressin (AVP) and the renin-angiotensin system support blood pressure when the sympathetic system is impaired pharmacologically or after epidural anesthesia. (utmb.edu)
  • There were two independent clinical trials including children and adults with autism that altered the effects of the hormone vasopressin and to assess the effects on social functioning. (news-medical.net)
  • Vasopressin is a man-made form of a hormone called "anti-diuretic hormone" that is normally secreted by the pituitary gland. (rexhealth.com)
  • We have also identified a novel vasopressin- signaling pathway that decreases the expression of steroid hormone inactivating enzymes in the collecting duct and propose that this vasopressin-mediated pathway may indirectly enhance ENaC expression. (elsevier.com)
  • Specific Aims are: 1) To determine if increases in local solute concentrations activate ER stress proteins and protect collecting duct cells from further osmotic stress 2) To determine if vasopressin directly mediates the up-regulation of ER stress proteins via a V2 receptor pathway 3) To determine if vasopressin directly mediates the down-regulation of steroid hormone enzymes via a V2 receptor pathway. (elsevier.com)
  • Circulating vasopressin plays a critical role in extra-cellular fluid expansion and development of hypertension, thus contributes to the pathogenesis of the disease. (elsevier.com)
  • Stimulation of hepatocytes with vasopressin evokes increases in cytosolic free Ca2+ ([Ca2+]c) that are relayed into the mitochondria, where the resulting mitochondrial Ca2+ ([Ca2+]m) increase regulates intramitochondrial Ca2+-sensitive targets. (unipd.it)
  • Thus we will determine if vasopressin plays a preconditioning role in the medulla to protect collecting duct cells from apoptosis while continuing to upregulate aquaporin-2 expression and increase collecting duct water permeability. (elsevier.com)
  • Methods: Healthy volunteers in whom epidural catheters were placed were randomly assigned to receive 1.25 mg intravenous enalapril or saline placebo followed by 0.5 mg AVP type V 1 antagonist β-mercapto-β,β-cyclopentamethylene-proprionyl-o-Met-Tyr-Arg- vasopressin (AVPA) or saline placebo. (utmb.edu)
  • Our studies will utilize three complementary model systems, cells, tubule suspensions and animal models to address our central hypothesis that vasopressin promotes AQP2- and ENaC-dependent pathways through direct (V2R) and indirect (osmotic stress) mechanisms. (elsevier.com)
  • It is possible that both sites are involved in vasopressin-dependent AQP2 trafficking. (anaspec.com)
  • anaphylaxis (cardiac arrest and/or shock ) has been observed shortly after injection of vasopressin. (rxlist.com)
  • abstract = "A recent study reported that protein synthesis was inhibited in rat livers perfused with medium containing vasopressin (Chin, K.-V., Cade, C., Brostrom, M. A., and Brostrom, C. O. (1988) Int. J. Biochem. (elsevier.com)
  • It is recommended to reconstitute the lyophilized Vasopressin in sterile 18MΩ-cm H2O not less than 100 µg/ml, which can then be further diluted to other aqueous solutions. (neobiolab.com)
Vasopressin News, Research
Vasopressin News, Research (news-medical.net)
Pitressin (Vasopressin): Uses, Dosage, Side Effects, Interactions, Warning
Pitressin (Vasopressin): Uses, Dosage, Side Effects, Interactions, Warning (rxlist.com)
Vasopressin | biochemistry | Britannica.com
Vasopressin | biochemistry | Britannica.com (britannica.com)
Vasopressin | Shock (Circulatory) | Medical Specialties
Vasopressin | Shock (Circulatory) | Medical Specialties (scribd.com)
Human endocrine system - Feedback regulation mechanisms of endocrine signaling | Britannica.com
Human endocrine system - Feedback regulation mechanisms of endocrine signaling | Britannica.com (britannica.com)
Human nervous system - The reproductive system | Britannica.com
Human nervous system - The reproductive system | Britannica.com (britannica.com)
Acute hyponatraemia in children admitted to hospital: retrospective analysis of factors contributing to its development and...
Acute hyponatraemia in children admitted to hospital: retrospective analysis of factors contributing to its development and... (bmj.com)
Sleep deprivation may cause dehydration
Sleep deprivation may cause dehydration (medicalnewstoday.com)
Calcium Channel Blocker Toxicity Medication: Antidotes, Other, Calcium Salts, Alpha/Beta Adrenergic Agonists, Alpha Adrenergic...
Calcium Channel Blocker Toxicity Medication: Antidotes, Other, Calcium Salts, Alpha/Beta Adrenergic Agonists, Alpha Adrenergic... (emedicine.medscape.com)
Plus it
Plus it (jneurosci.org)
A-Z Drug Index for Prescription and OTC Medications - Alphabet V
A-Z Drug Index for Prescription and OTC Medications - Alphabet V (medindia.net)
AVP gene - Genetics Home Reference - NIH
AVP gene - Genetics Home Reference - NIH (ghr.nlm.nih.gov)
Vasopressin Emerges as Hormone of Interest in Autism Research - Scientific American
Vasopressin Emerges as Hormone of Interest in Autism Research - Scientific American (scientificamerican.com)
What Happens to Your Brain When You Have Sex | Reader's Digest
What Happens to Your Brain When You Have Sex | Reader's Digest (rd.com)
Vasopressin News, Research - Page 3
Vasopressin News, Research - Page 3 (news-medical.net)
10 Interesting Facts About Falling In Love From Modern Science - Listverse
10 Interesting Facts About Falling In Love From Modern Science - Listverse (listverse.com)
Vasopressin and the Social Brain - Full Text View - ClinicalTrials.gov
Vasopressin and the Social Brain - Full Text View - ClinicalTrials.gov (clinicaltrials.gov)
Wheeless' Textbook of Orthopaedics
Wheeless' Textbook of Orthopaedics (wheelessonline.com)
April 1996 - Volume 3 - Issue 2 : Current Opinion in Endocrinology, Diabetes and Obesity
April 1996 - Volume 3 - Issue 2 : Current Opinion in Endocrinology, Diabetes and Obesity (journals.lww.com)
Orexin - Wikipedia
Orexin - Wikipedia (en.wikipedia.org)
Ethylenediaminetetraacetic acid - Wikipedia
Ethylenediaminetetraacetic acid - Wikipedia (en.wikipedia.org)
Team:RMIT Australia/Project - 2010.igem.org
Team:RMIT Australia/Project - 2010.igem.org (2010.igem.org)
Centrally released oxytocin mediates mating-induced anxiolysis in male rats | PNAS
Centrally released oxytocin mediates mating-induced anxiolysis in male rats | PNAS (pnas.org)
Regulation of the Sympathetic Nervous System by Circulating Vasopressin | SpringerLink
Regulation of the Sympathetic Nervous System by Circulating Vasopressin | SpringerLink (link.springer.com)
Cardiogenic shock: MedlinePlus Medical Encyclopedia
Cardiogenic shock: MedlinePlus Medical Encyclopedia (medlineplus.gov)
Shop and Discover over 51,000 Books and Journals - Elsevier
Shop and Discover over 51,000 Books and Journals - Elsevier (elsevier.com)
Behaviour 2013 | Cambridge University Press
Behaviour 2013 | Cambridge University Press (cambridge.org)
Animal Behaviour, Biological Anthropology and Primatology | Cambridge University Press
Animal Behaviour, Biological Anthropology and Primatology | Cambridge University Press (cambridge.org)
Vasopressin - WellSpan Health Library
Vasopressin - WellSpan Health Library (wellspan.org)
MedlinePlus: Genes
MedlinePlus: Genes (medlineplus.gov)