The nature of the adrenoceptors in the post-partum rat uterus.
1. Uteri were removed from rats 0.5 h to 8 days after parturition and were suspended in Locke solution at 37 degrees C.2. The agonists isoprenaline, adrenaline, noradrenaline and phenylephrine produced an inhibition of the post-partum rat uterus.3. In the presence of propranolol, the agonists noradrenaline, adrenaline, and phenylephrine had an excitatory effect on the post-partum rat uterus. This excitatory effect was blocked by phenoxybenzamine indicating that it is mediated through alpha-adrenoceptors.4. These excitatory alpha-adrenoceptors could be demonstrated for 5-6 days after parturition. By the 7th-8th days their existence was no longer apparent.5. Excitatory alpha-adrenoceptors were also demonstrated in the late pregnant rat uterus.
D000200:Action Potentials; D000818:Animals; D004357:Drug Synergism; D004837:Epinephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D007743:Labor, Obstetric; D009638:Norepinephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D010643:Phenoxybenzamine / Q000494:pharmacology; D010656:Phenylephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D049590:Postpartum Period; D011247:Pregnancy; D011433:Propranolol / Q000037:antagonists & inhibitors / Q000494:pharmacology; D051381:Rats; D011941:Receptors, Adrenergic; D011955:Receptors, Drug; D013564:Sympathetic Nervous System / Q000187:drug effects; D013997:Time Factors; D014599:Uterus / Q000187:drug effects*
D011941:Receptors, Adrenergic; D011955:Receptors, Drug; D010643:Phenoxybenzamine; D010656:Phenylephrine; D011433:Propranolol; D007545:Isoproterenol; D009638:Norepinephrine; D004837:Epinephrine