Estradiol-induced increase of specific [3H]ketanserin binding sites on rat uterine membranes.
[3H]Ketanserin, a specific serotonin (5-HT) antagonist, was used to investigate whether 5-HT receptors increased in the uterine membranes of ovariectomized rats on administration of 17 beta-estradiol-3-benzoate (estradiol) and also to investigate the characteristics of specific [3H]ketanserin binding to the uterine membranes from estradiol-treated ovariectomized rat. Administration of estradiol significantly increased the amount of [3H]ketanserin specifically bound at equilibrium but did not change the apparent affinity of specific [3H]ketanserin binding. The specific [3H]ketanserin binding to estradiol-treated ovariectomized preparations was rapid and reversible. The Scatchard plots of the saturation curves of specific [3H]ketanserin binding to untreated and estradiol-treated ovariectomized preparations were convex. The apparent Ki values of various serotonergic agents deduced from displacements by these compounds of specific [3H]ketanserin binding to estradiol-treated ovariectomized preparations were two to four orders of magnitude smaller than those of adrenergic, dopaminergic and histaminergic agents. These results suggest that [3H]ketanserin binds mainly to 5-HT receptors in the uterine membranes of estradiol-treated ovariectomized rats.
Ichida
S
S
Hayashi
T
T
Kita
T
T
Murakami
T
T
D000818:Animals; D001665:Binding Sites; D002369:Castration; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D007650:Ketanserin; D008566:Membranes / Q000378:metabolism; D010880:Piperidines / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000378:metabolism*; D014316:Tritium; D014599:Uterus / Q000378:metabolism*
D010880:Piperidines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D014316:Tritium; D004958:Estradiol; D007650:Ketanserin