Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The neurohypophyseal hormone oxytocin (OT) is the most potent uterotonic agent known and is used to induce labor. Yet, endogenous circulating OT appears not to participate in the induction of labor. As shown here, the finding of OT messenger RNA and peptide in the uterus suggests a solution for this paradox. During gestation, rat uterus OT messenger RNA increased more than 150-fold and, at term, exceeded hypothalamic OT messenger RNA by 70-fold. Thus, during parturition, OT may act primarily as a local mediator and not as a circulating hormone.
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PMID:Oxytocin gene expression in rat uterus. 159 87

The type of antagonism exhibited by three novel bradykinin (BK) antagonists, D-Arg-[Hyp3,Thi5,D-Tic7,Oic8]BK (HOE 140, compound I), D-Arg-[Hyp3,D-Tic7,Oic8]BK (compound II) and [Arg(Tos)1,Hyp3,Thi5,D-Tic7,Oic8]BK (compound III), was compared with that of a conventional antagonist, D-Arg-[Hyp2,Thi5,8,D-Phe7]BK (compound IV), on the guinea-pig ileum. The novel compounds induced rightward displacements of cumulative concentration-response curves to BK, accompanied by a progressive reduction of the maximum effect (Emax) without a significant decrease in the slope, whereas no reduction of Emax was observed with compound IV. Actions of substance P on the guinea-pig ileum and of vasopressin on the rat uterus remained completely unaffected. It is concluded that as the novel BK analogues show competitive as well as non-competitive inhibition in the guinea-pig ileum, but the inhibition is reversible and specific, they are dual antagonists.
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PMID:Analysis of the antagonistic actions of HOE 140 and other novel bradykinin analogues on the guinea-pig ileum. 161 75

1. The potencies of several neurohypophysial hormones were examined at different times during the oviposition cycle in an in vitro fowl oxytocic assay. 2. Uterine tissues were removed 2 h before (-2h-OP), immediately after (0h-OP) and 5 h after (+5h-OP) spontaneous oviposition. In addition, uterine tissue was removed immediately after oviposition was induced, by administering prostaglandin E2 2 h before an expected oviposition (Induced-OP). 3. The rank order of oxytocic potencies for the peptides was arginine vasotocin = vasopressin greater than oxytocin greater than mesotocin. The sensitivity of the uterus to the hormones was 0h-OP = Induced-OP greater than -2h-OP = +5-OP. 4. These results suggest that uterine sensitivity to neurohypophysial hormones changes during the oviposition cycle in domestic fowls.
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PMID:Alterations in uterine contractility during the oviposition cycle in domestic hens. 164 29

Oxytocin (OT) and V1 vasopressin (VP) receptors are present simultaneously in several tissues, including the uterus. In myometrium these receptors mediate contractility, while in endometrium they mediate the release of other uterotonic substances as endothelin (ET). In rabbit myometrium, estrogens increase, while progesterone blunts neurohypophysial hormone receptors. However, the action of sex steroids on OT and V1 VP receptors differs in terms of the ED50 and maximal effect. Therefore, at parturition, only OT receptors show a dramatic rise, while V1 VP receptors do not change, suggesting a major role for OT in labor. ET is a potent stimulator of uterine activity acting through specific receptors present on myometrial cells. These receptors as well as the endometrial localization of ET are modulated by sex steroids, indicating that ET might represent a paracrine regulator of uterine activity. In humans, OT but not V1 VP receptors increase as pregnancy progresses, confirming the primary relevance of OT in timing delivery.
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PMID:Steroid modulation of oxytocin/vasopressin receptors in the uterus. 165 85

We previously reported that pregnancy and progesterone treatment abolish and ovariectomy reduces the tocolytic activity of atrial natriuretic factor (ANF) on rat uterus. The present study was carried out to determine whether the hormonal state of the animal influences myometrial ANF receptors. A single high-affinity binding site for 125I-labelled ANF(1-28) was detected in myometrial membrane preparations partially purified by discontinuous sucrose gradient centrifugation. The specifically bound ANF could be displaced completely by unlabelled ANF(1-28) (biologically active circulating form of ANF), partially (approximately 50%) by the clearance receptor (ANF-R2) ligand, ANF(4-23), and insignificantly by angiotensin II, vasopressin, carbachol and progesterone. Maximum binding capacities (fmol/mg protein +/- S.E.M.) of myometrial membrane preparations for ANF were as follows: vehicle-treated cyclic rats, 30.2 +/- 5.9 (n = 6); oestrogen-treated virgin rats, 55.8 +/- 7.1 (n = 8); progesterone-treated virgin rats, 21.9 +/- 2.4 (n = 6); 20-day pregnant rats, 18.9 +/- 4.3 (n = 4); ovariectomized rats, undetectable (n = 3); ovariectomized rats treated with oestrogen, 50.2 +/- 4.1 (n = 3); virgin rats treated with progesterone antagonist RU 486, 64.5 +/- 5.2 (n = 3). Relative to cyclic rats, oestrogen and RU 486 caused a significant (P less than 0.05) increase and progesterone and pregnancy caused a significant (P less than 0.05) decrease in ANF myometrial receptors. The hormonal state did not change dissociation constants for ANF binding to myometrial preparations.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Down-regulation of myometrial atrial natriuretic factor receptors by progesterone and pregnancy and up-regulation by oestrogen in rats. 166 May 19

Previous studies of marsupial lactation have shown that the milk-ejection reflex changes in sensitivity, being greater in small mammary glands sucked by small pouch young and lesser in larger glands supplying milk to larger young. The involvement of oxytocin receptors in these changes was examined in the brushtail possum Trichosurus vulpecula. Oxytocin receptors were measured in the mammary glands, uterus, and medial vaginal sacs by radioreceptor assay, using [3H]oxytocin as radioligand. In the mammary gland, a single oxytocin binding site was found with an affinity and receptor concentration of 0.81 +/- 0.41 l/nmol and 10.2 +/- 4.8 pmol/g tissue respectively (SD, 10 possums). Competitive displacement curves with related peptides and analogs showed the following order of specificity: d(CH2)5[Tyr(Me)2,Thr4,Tyr9-NH2]-vasotocin much greater than vasotocin greater than oxytocin = Arg-vasopressin greater than mesotocin greater than [Thr4,Gly7]-oxytocin = Lys-vasopressin greater than [deamino-Pen1, O-methyl-Tyr2, Arg8]-vasopressin greater than isotocin much greater than [d(CH2)5, D-Phe2, Ile4, Ala9-NH2]-AVP. [3H]Oxytocin did not bind to vasopressin receptors in the thoracic aorta. The concentration of oxytocin receptors was very high in small mammary glands (18.6 pmol/g tissue in a 2-g gland) and decreased logarithmically as the size of the mammary gland increased. It is suggested that the changes in the sensitivity of milk ejection to oxytocin is related to the concentration of mammary oxytocin receptors. The presence of oxytocin receptors in both uterus and median vaginal sacs extends previous observations and supports the hypothesis that in marsupial parturition, the uterus and medial vaginal sacs respond as a single functional unit to oxytocin.
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PMID:Oxytocin receptors in the mammary gland and reproductive tract of a marsupial, the brushtail possum (Trichosurus vulpecula). 166 15

A linear vasopressin antagonist, Phaa-D-Tyr(Me)-Phe-Gln-Asn-Arg-Pro-Arg-Tyr-NH2 (Linear AVP Antag) (Phaa = Phenylacetyl), was monoiodinated at the phenyl moiety of the tyrosylamide residue at position 9. This antagonist appeared to be a highly potent anti-vasopressor peptide with a pA2 value in vivo of 8.94. It was demonstrated to bind to rat liver membrane preparations with a very high affinity (Kd = 0.06 nM). The affinity for the rat uterus oxytocin receptor was lower (Ki = 2.1 nM), and affinities for the rat kidney- and adenohypophysis-vasopressin receptors were much lower (Ki = 47 nM and 92 nM, respectively), resulting in a highly specific vasopressin V1a receptor ligand. Autoradiographical studies using rat brain slices showed that this ligand is a good tool for studies on vasopressin receptor localization and characterization.
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PMID:A radioiodinated linear vasopressin antagonist: a ligand with high affinity and specificity for V1a receptors. 182 14

Obstetrician-gynecologists from the University of California at Davis have managed uterine bleeding in 2 cases using vasopressin and hysteroscopy. The postabortion case began hemorrhaging 4 days after suction curettage at 13 weeks gestation. At the hospital, she received packed blood cells and underwent dilation and curettage (D&C). After 3 days of bed rest at home, she began rehemorrhaging. In the emergency room, she again underwent a transfusion. They prepared her for a laparotomy and either hypogastric artery ligation or hysterectomy. Before surgery, however, they opted to inject vasopressin around the cervix and to use a resectoscope to determine the cause of bleeding. The bleeding diminished after injection of vasopressin. They observed arterial bleeding. They used an electrode set at 100 W to coagulate bleeding points, then packed the uterus with gauze soaked in dilute vasopressin solution. They removed the pack 18 hours later. After 2 hours bed rest with no additional bleeding, she became ambulatory. Since no additional bleeding occurred, she was discharged. After 8 months, she continued to experience normal menses. The postpartum case began to bleed profusely 21 days after a cesarean section. Physicians handled her case similarly to the postabortion case. They tried a hysteroscopy, but being unable to see due to heavy bleeding they injected vasopressin paracervically. The blood flow decreased substantially within a few minutes allowing them to use a resectoscope. Placental tissue and amniotic membranes were still present in the uterus and removed. Using the same procedures of the postabortion case, they coagulated the bleeding points and packed the uterus with gauze. She did not experience any significant bleeding for 24 hours so she was discharged. Normal menses resumed and, as of 4 months after discharge, she was fine.
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PMID:Vasopressin and operative hysteroscopy in the management of delayed postabortion and postpartum bleeding. 189 87

1. Oxytocin receptors in the uterus of the brushtail possum (T. vulpecula) were characterized by radioreceptor assay and compared with those of the sheep and rat uterus. 2. A single oxytocin binding site was found with an affinity (Kd) and receptor concentration (Ro) of 3.0 +/- 0.8 nmol/l and 200 +/- 60 fmol/mg protein, respectively (SEM; n = 5). The receptor was stable at -20 degrees C; divalent ions were required for optimum binding. 3. Competitive displacement curves with related peptides showed the following order of specificity: vasotocin greater than oxytocin greater than mesotocin = arginine-vasopressin = [Thr4, Gly7]-oxytocin greater than lysine-vasopressin = isotocin much greater than [d(CH2)5, D-Phe2, Ile4, Ala9-NH2]-AVP. 4. It was concluded that oxytocin receptors in the possum have similar characteristics to those of placental mammals.
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PMID:Uterine oxytocin receptors in an Australian marsupial, the brushtail possum, Trichosurus vulpecula. 196 6

1. Effects of atrial natriuretic peptide (ANP) on tension development, particulate guanylate cyclase activity and guanosine 3':5'-cyclic monophosphate (cyclic GMP) concentrations of uteri from oestrogen-treated, progesterone-treated, ovariectomized and pregnant rats were determined in vitro. 2. ANP inhibited the tension development by myometrial tissues from oestrogen-treated virgin rats and the sterile horn of 10 to 14 day pregnant rats but not of the uterus from pregnant and progesterone-treated rats. 3. Inhibition of cyclo-oxygenase and lipoxygenase activities did not restore the tocolytic activity of ANP on gravid uterus. ANP exerted a tocolytic effect on nongravid uterus submaximally stimulated by prostaglandin F2 alpha (PGF2 alpha), oxytocin, vasopressin, angiotensin II or 5-hydroxytryptamine (5-HT). 4. Ovariectomy decreased the tocolytic effects of ANP, which could be restored by oestrogen treatment. 5. The refractoriness to the tocolytic effect of ANP in pregnant rats was not accompanied by a decrease in its relaxant effects on isolated aortic strips. 6. Tocolytic effects of isoprenaline, isobutylmethyl xanthine and hydroxylamine were not influenced by pregnancy or progesterone treatment. Up to a concentration of 3 mM, sodium nitroprusside did not affect myometrial tension development. 7. Pregnancy and progesterone treatment markedly inhibited ANP-induced increases in myometrial particulate guanylate cyclase activity and cyclic GMP concentrations but did not influence the effects of ANP on aortic cyclic GMP concentrations. 8. It is concluded that exposure of the myometrium to circulating and placentally-produced progesterone is responsible for the pregnancy-induced decrease in the effects of ANP on myometrial particulate guanylate cyclase activity and cyclic GMP concentrations and in turn on myometrial tension development.
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PMID:Refractoriness of the gravid rat uterus to tocolytic and biochemical effects of atrial natriuretic peptide. 197 61


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