A Comparison of the Oxytocic Effects of Synthetic Vasopressin and Oxytocin

Embrey, M. P.; Moir, J. Chassar

doi:10.1111/j.1471-0528.1967.tb03775.x

Cited by 38 publications

(16 citation statements)

References 3 publications

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“…In the nonpregnant human uterus, AVP exerts stronger oxytocic actions than OT [3,4], and there are distinctly different OT and VP receptors in human myometrium [8,9]. However, our results did not rule out the possibility of a small concentration of VP receptors in porcine longitudinal myometrium.…”

Section: Discussioncontrasting

confidence: 72%

“…OT increases myometrial contractility in both pregnant and nonpregnant uteri, but its action on the nonpregnant human uterus is weaker and is inconsistent [1,2]. In contrast, VP causes greater myometrial contractility in the nonpregnant than in the pregnant human uterus [3,4], suggesting that VP and its receptors may play an important role in the regulation of myometrial contractility, particularly in nonpregnant uteri.…”

Section: Introductionmentioning

confidence: 96%

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Lysine Vasopressin-Induced Increases in Porcine Myometrial Contractility and Intracellular Ca2+ Concentrations of Myometrial Cells: Involvement of Oxytocin Receptors1

ZhuGe

Hsu

1995

Biology of Reproduction

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The present study was undertaken to investigate whether lysine vasopressin (LVP) induces porcine myometrial contractions by activating vasopressin or oxytocin (OT) receptors. Both LVP (3 x 10(-9)-10(-6) M) and OT (3 x 10(-11)-10(-8) M) increased contractility dose-dependently in myometrium from both the luteal phase and prepartum period. Comparison of EC50s showed that OT was 75 and 57 times more potent than LVP in increasing myometrial contractility in pregnant and nonpregnant sows, respectively. L-366,948 (10(-8), 3 x 10(-8), 10(-7) M), a highly selective OT receptor antagonist, inhibited LVP- and OT-induced increases in myometrial contractility dose-dependently in both pregnant and nonpregnant tissues with similar antagonist affinity values (pA2). The V1 antagonist d(CH2)5[D-[Tyr(Me)2]AVP also antagonized both LVP- and OT-induced increases in myometrial contractility, but higher concentrations (10(-7) and 10(-6) M) were required to achieve the antagonism. The V2 antagonist Aaa-D-Tyr(Et)-Phe-Val-Asn-Abu-Pro-Arg-Arg-NH2 (10(-6) M) did not alter this effect of LVP and OT. LVP (10(-9)-10(-6) M) and OT (10(-10)-10(-7) M) also increased intracellular Ca2+ ([Ca2+]i) concentrations in porcine myometrial cells from sows during the prepartum period in a dose-dependent manner, with OT being 14 times more potent than LVP. L-366,948 (10(-9)-3 x 10(-8) M) antagonized the effect of OT (10(-7) M) and LVP (10(-6) M) in a similar dose-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Discussioncontrasting

confidence: 72%

Section: Introductionmentioning

confidence: 96%

Lysine Vasopressin-Induced Increases in Porcine Myometrial Contractility and Intracellular Ca2+ Concentrations of Myometrial Cells: Involvement of Oxytocin Receptors1

ZhuGe

Hsu

1995

Biology of Reproduction

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“…The lack of correlation between data from non-pregnant and pregnant women is not surprising in view of the different sensitivity to oxytocin and vasopressin of the human uterus in non-pregnant and pregnant conditions (Embrey & Moir, 1967;Continho & Lopes, 1968). Thus some analogues had different inhibiting potencies on the two human prep¬ arations (Fig.…”

Section: Discussionmentioning

confidence: 93%

“…The buffer was Krebs-Ringer solution (1-5 mmol/1) at 37°C. Because of differences in sensi¬ tivity to posterior pituitary hormones (Embrey & Moir, 1967), arginine vasopressin and oxytocin were used as agonists (0-1 pmol/1) on tissue preparations from non-pregnant women and pregnant women at term respectively. A dose of the agonist was given either alone or 2 min after a dose of standard d(OEt)-oxytocin or a test analogue.…”

Section: Pharmacological Methodsmentioning

confidence: 99%

Synthetic antagonists of the myometrial response to vasopressin and oxytocin

Melin¹,

Trojnar²,

Johansson³

et al. 1986

Journal of Endocrinology

146

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With the aim of developing inhibitors of vasopressin- and oxytocin-induced uterine activity, 17 analogues of 1-deamino-oxytocin were synthesized by the solid-phase method. Modifications were made at positions 2, O-methyltyrosine (Tyr(OMe] and O-ethyltyrosine (Tyr(OEt],D-Tyr,D-Tyr(OEt),D-Trp; 4, Val,Thr and 8, Orn,Cit,Arg,D-Arg. The analogues were tested for antiuterotonic activity in vitro and in vivo in the rat and in vitro on myometrial strips from non-pregnant women and pregnant women at term. Their selectivity was also investigated in blood pressure and antidiuretic bioassays in rats. Results were compared with those from an original antiuterotonic analogue 1-deamino-2-Tyr(OEt)-oxytocin (d(OEt)-oxytocin). In the rat in vitro and in vivo all analogues possessed higher antiuterotonic activity than d(OEt)-oxytocin. The negative logarithm of the molar concentration of the antagonist which reduced the effect of a dose of agonist to that of half the dose (pA2) was between 7.6 and 8.9 for all the new inhibitors compared with 7.2 for d(OEt)-oxytocin. The highest pA2 value was found for 1-deamino-2-Tyr(OMe)-8-Orn-oxytocin (8.9 +/- 0.2, S.E.M.) and 1-deamino-2-Tyr(OEt)-4-Thr-8-Orn-oxytocin (8.9 +/- 0.6). In myometrium from non-pregnant women the most potent peptide was 1-deamino-2-D-Tyr(OEt)-4-Thr-8-Orn-oxytocin (17.2 +/- 2.0 times more potent that d(OEt)-oxytocin). In myometrium from pregnant women the inhibitory effects of the majority of the analogues were less pronounced.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…The course of pregnancy is not affected by the appear ance of DI or by vasopressin therapy [6], but pregnancy itself can cause exacerbation of the disease [7,8], Among the causes are increased levels of progesterone and ste roids which antagonized ADH, changes in renal func tion, existence of 'pitressinases' or compression of the posterior hypothysis by the enlarged anterior hypophysis [7,9]. In only 20% of the women was an improvement of the disease described [7,8].…”

Section: Discussionmentioning

confidence: 99%

Pregnancy in Panhypopituitarism

Golan¹,

Abramov²,

Yedwab³

et al. 1990

Gynecol Obstet Invest

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The case of a 30-year-old pregnant patient suffering from panhypopituitarism is presented. Pregnancy induced by HMG/HCG had been uneventful. Induction of labor by PGE₂ vaginal tablets and by intravenous oxytocin at 42 gestational weeks failed and the patient was operated. Following the operation severe exacerbation of her diabetes insipidus occurred. Fluid balance mechanism failed and electrolyte status deteriorated rapidly. The importance of pitressin in maintenance of fluid and electrolyte balance in panhypopituitaric patients in labor and surgical trauma is stressed.

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A Comparison of the Oxytocic Effects of Synthetic Vasopressin and Oxytocin

Cited by 38 publications

References 3 publications

Lysine Vasopressin-Induced Increases in Porcine Myometrial Contractility and Intracellular Ca2+ Concentrations of Myometrial Cells: Involvement of Oxytocin Receptors1

Lysine Vasopressin-Induced Increases in Porcine Myometrial Contractility and Intracellular Ca2+ Concentrations of Myometrial Cells: Involvement of Oxytocin Receptors1

Synthetic antagonists of the myometrial response to vasopressin and oxytocin

Pregnancy in Panhypopituitarism

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