Increase by oestrogen of calcium entry and calcium channel density in uterine smooth muscle.
1 The effect of in vivo oestrogen treatment on both 45Ca influx in myometrial strips and the kinetics of [3H)-nitrendipine binding in the isolated plasma membrane (PM) was studied. 2 After four days of continuous oestrogen treatment of ovariectomized rats, 45Ca influx in both resting (unstimulated) and K-stimulated myometrium was substantially increased. 3 Oestrogen treatment significantly increased the density in PM of nitrendipine binding sites and also caused a slight and insignificant increase in the affinity for nitrendipine. 4 The data suggest that the increase in Ca entry following oestrogen treatment probably results from an increase in calcium channel density.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism*; D009568:Nitrendipine / Q000378:metabolism; D010052:Ovariectomy; D051381:Rats; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D014599:Uterus / Q000187:drug effects / Q000378:metabolism
D004967:Estrogens; D007473:Ion Channels; D009568:Nitrendipine; D002118:Calcium