Betamimetic effects on the electro-mechanical characteristics of the pregnant and postpartum myometrium in vitro.
Myometrial strips were studied in the two extremes of regulatory conditions by measuring isometric tension and resting potentials in vitro. The effects of isoproterenol (IP) and PGF2 alpha were studied on pregnant and postpartum rabbit uteri. Lower IP concentrations inhibited the activity of the pregnant uterus as compared to the postpartum myometrium. Both pregnant and postpartum myometrium could be hyperpolarized by IP, however, lower concentrations were needed during pregnancy. The inhibiting effect on mechanical activity of IP developed without any hyperpolarization at its lower concentration.
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D000818:Animals; D001696:Biomechanical Phenomena; D015237:Dinoprost; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D005260:Female; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009215:Myometrium / Q000187:drug effects*; D049590:Postpartum Period; D011247:Pregnancy; D011460:Prostaglandins F / Q000494:pharmacology; D011817:Rabbits; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D014590:Uterine Contraction / Q000187:drug effects
D011460:Prostaglandins F; D011943:Receptors, Adrenergic, beta; D015237:Dinoprost; D007545:Isoproterenol