Effects of hormonal treatments which alter ovum transport on beta-adrenoceptors of the rabbit oviduct.
Beta-Adrenoceptor activity of rabbit oviductal isthmus has been determined quantitatively in vitro in tissues isolated 24 and 72 hours after human chorionic gonadotropin injection and after two hormonal treatments known to accelerate (progesterone) and retard (estrogen) ovum transport. Under conditions in which ova are located at the ampullary-isthmic junction and distal isthmus, the isthmus demonstrates a low incidence of spontaneous activity in vitro, poor response to acetylcholine, low affinity of beta-adrenoceptors for isoproterenol, and low efficacy of isoproterenol to inhibit acetylcholine-induced contractions. Under conditions in which ova are passing into the uterus, the isthmus shows the converse of these parameters. These data support the hypotheses that the oviductal isthmus functions as an adrenergic sphincter and that the actions of progesterone and estrogen in altering ovum transport rates are at least partially mediated through changes in adrenoceptors.
D000109:Acetylcholine / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001692:Biological Transport; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology; D004971:Estrus / Q000187:drug effects; D005187:Fallopian Tubes / Q000187:drug effects*; D005260:Female; D006728:Hormones / Q000494:pharmacology*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D010063:Ovum / Q000187:drug effects* / Q000502:physiology; D011247:Pregnancy; D011270:Pregnancy, Animal; D011374:Progesterone / Q000494:pharmacology; D011555:Pseudopregnancy / Q000187:drug effects; D011817:Rabbits; D013618:Tachyphylaxis
D000319:Adrenergic beta-Antagonists; D006063:Chorionic Gonadotropin; D004967:Estrogens; D006728:Hormones; D011374:Progesterone; D007545:Isoproterenol; D000109:Acetylcholine