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 effects of pregnancy and placental localization on vascular responses to endogenous vasoconstrictor agents were studied in intramyometrial arteries dissected from myometrial biopsies. The tissues were taken from the lower uterine segment in patients subjected to hysterectomy (n = 8), and in pregnant patients undergoing caesarean section without (n = 8) and with low anterior placental insertion/placenta previa (n = 8). Isometric tension was recorded in vascular ring preparations mounted in organ baths and the contractile effects of angiotensin II, noradrenaline, vasopressin and the TxA2-mimic U46619 were studied. No differences in contractile responses between vessels from the three patient groups were found. When comparing vessels from all the pregnant patients with those from non-pregnant patients, vasopressin showed lower Emax values in preparations from the pregnant women, but otherwise no differences were found. The pD2 values (= -log EC50) ranked the agonists vasopressin greater than U46619 greater than or equal to angiotensin II greater than or equal to noradrenaline (U46619 greater than noradrenaline), while no major differences emerged for the Emax values. The results do not provide evidence that pregnancy and placental localization produce major changes in intramyometrial vascular responses to endogenous vasoconstrictor agents of suggested importance for regulation of human maternal placental resistance.
Placenta
PMID:Vascular responses in term pregnant and non-pregnant human uterus. 203 95

The effects of vasoactive intestinal polypeptide (VIP) and substance P on isolated human intramyometrial arteries and fetal stem villous arteries obtained from term pregnant women were compared. Ring preparations of small intramyometrial arteries and fetal stem villous arteries obtained at caesarean section were mounted in organ baths, and isometric tension was recorded. None of the peptides affected resting tension. In intramyometrial arteries precontracted by vasopressin (2.8 x 10(-9) M) both substance P (10(-12) to 10(-8) M) and VIP (10(-8) to 10(-6) M) caused relaxation. In fetal stem villous arteries precontracted by prostaglandin F2 alpha (10(-5) M) cumulative addition of substance P (10(-11) to 10(-6) M) did not produce significant changes in tension as compared with controls, while addition of single doses produced moderate relaxation. VIP (10(-8) to 10(-6) M) induced relaxation with similar effects for the addition of cumulative and single doses. The responses to VIP and substance P remained unaffected after pretreatment by atropine (10(-6) M), propranolol (10(-6) M), and indomethacin (10(-6) M). The results support a role for VIP and substance P in the regulation of uteroplacental blood flow in term pregnancy.
Placenta
PMID:Effects of vasoactive intestinal polypeptide and substance P on human intramyometrial arteries and stem villous arteries in term pregnancy. 246 22

The interactions of corticotrophin releasing factor (CRF) and oxytocin on myometrial contractility were studied in isolated gestational myometrium in vitro. Acting alone oxytocin showed a significant dose related inotropic effect (P less than 0.001), whereas CRF did not. Dose-response curves of oxytocin in the presence of a fixed dose of CRF showed a threefold increase in the response to oxytocin without CRF present (P = 0.0019). When this combined priming and potentiating effect was investigated separately, priming of the myometrial strips with CRF prior to stimulation with oxytocin significantly enhanced the inotropic effect of oxytocin (P = 0.01) and when given together a significant potentiating effect was seen (P = 0.008). It is suggested that placental CRF may act as an important modulator of the inotropic effect of oxytocin on myometrium. The interaction between the two peptides may be similar to that which occurs between CRF and vasopressin in the anterior pituitary gland.
Placenta
PMID:Placental corticotrophin releasing factor may modulate human parturition. 278 79

SR49059 is an antagonist of vasopressin V(1a)receptors currently developed as a tocolytic drug. We investigated the transplacental transfer of SR49059 in vitro using the single pass dually perfused human cotyledon model. Thirteen placentae were collected from normal term pregnancies immediately after delivery. The placental transfer of SR49059 was tested at steady state at three different concentrations (100 ng/ml, 200 ng/ml and 500 ng/ml) along with that of antipyrine 20 mg/l as a reference substance. Concentrations were assayed by liquid chromatography with UV (antipyrine) or mass spectrometry (SR49059) detection. At steady state, the mean+/-s.d. fetal transfer rate of SR49059 was 10.80+/-4.33 per cent, 9.34+/-4.41 per cent, and 11.78+/-3.26 per cent at 100 ng/ml, 200 ng/ml and 500 ng/ml, respectively. The corresponding clearance indices were 0.29+/-0.14, 0.25+/-0.08, and 0.31+/-0.06, respectively. The absence of saturation kinetics is consistent with a passive mechanism of transfer. Moderate amounts of SR49059 are transferred from the maternal to the fetal circulation. The clearance index of SR49059 appeared to be very similar to that of ritodrine, which is currently used as a tocolytic.
Placenta 2001 Nov
PMID:Placental transfer of SR49059 in the human dually perfused cotyledon in vitro. 1171 75