Parathyroid hormone-related peptide inhibits oxytocin-induced rat uterine contractions in vitro.
Synthetic human parathyroid hormone-related peptide (hPTHrP)-(1-34) fragment was compared with parathyroid hormone (bovine sequence, 1-34; bPTH-(1-34) for inhibiting oxytocin or prostaglandin F2 alpha (PGF2 alpha)-induced contractions on rat uterus in vitro. bPTH exhibited a potent (ED50 = 7 x 10(-9) M) inhibition on oxytocin-induced contractions. Both bPTH-(1-34) and hPTHrP-(1-34) were devoided of any significant effect upon PGF2 alpha-induced uterine contractions. Human PTHrP also inhibited oxytocin-induced uterine contractions (ED50 = 77 x 10(-9) M) and this effect, like that of bPTH, was dose dependent. Human PTHrP-(140-173) fragment had no significant effect on oxytocin-induced uterine contractions. The inhibitory effect of hPTHrP-(1-34) disappeared after pretreatment with [Tyr]34-bPTH-(7-34)-NH2, a competitive reversible antagonist of bPTH-(1-34). Thus PTHrP might be involved in the control of myometrial activity.
Dalle
M
M
Laboratoire de Physiologie Animale, Université Blaise Pascal, Aubière, France.
Dauprat-Dalle
P
P
Barlet
J P
JP
D000818:Animals; D015237:Dinoprost / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006728:Hormones / Q000494:pharmacology; D009363:Neoplasm Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D010121:Oxytocin / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D010281:Parathyroid Hormone / Q000008:administration & dosage / Q000494:pharmacology; D044162:Parathyroid Hormone-Related Protein; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D011506:Proteins; D051381:Rats; D017208:Rats, Wistar; D014590:Uterine Contraction / Q000187:drug effects*
D006728:Hormones; D009363:Neoplasm Proteins; D010281:Parathyroid Hormone; D044162:Parathyroid Hormone-Related Protein; D010446:Peptide Fragments; D011506:Proteins; C054296:parathyroid hormone-related protein (1-34); C025076:parathyroid hormone (1-34), bovine; D010121:Oxytocin; D015237:Dinoprost