Influence of chronic oestrogen treatment on the density of muscarinic cholinergic receptors and calcium channels in the rabbit uterus.
Ovariectomized rabbits were treated for 1 or 8 weeks with oestrogen and the effects on uterine weight, muscarinic receptor density and nitrendipine-binding sites on myometrial membranes were studied. The wet weight of the uterus after 1 week of oestrogen treatment increased more than tenfold and increased further by approximately 50% after 8 weeks of oestrogen treatment. The muscarinic receptor density increased significantly after 1 week of oestrogen treatment. Although there was no further increase in receptor density with continuing oestrogen treatment up to 8 weeks, the muscarinic receptor affinity increased significantly. The density of nitrendipine-binding sites increased sixfold after 1 week of oestrogen treatment and did not change thereafter. Oestrogen treatment had no influence on the affinity of nitrendipine-binding sites. The increase by oestrogen in muscarinic receptor density and in nitrendipine-binding sites as shown by the present data is consistent with the generally reported increase in agonist-induced contractile response of the myometrium following oestrogen treatment.
Batra
S
S
Department of Obstetrics and Gynaecology, University Hospital, Lund, Sweden.
D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D015220:Calcium Channels / Q000187:drug effects* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D009215:Myometrium / Q000378:metabolism; D009568:Nitrendipine / Q000378:metabolism; D010052:Ovariectomy; D011817:Rabbits; D011976:Receptors, Muscarinic / Q000187:drug effects* / Q000378:metabolism; D014599:Uterus / Q000187:drug effects* / Q000378:metabolism
D015220:Calcium Channels; D011976:Receptors, Muscarinic; D004958:Estradiol; D009568:Nitrendipine