Hormonal regulation of rat seminal vesicle sensitivity to adrenaline, noradrenaline, acetylcholine and acetyl-β-methylcholine

Open Access
Publisher Website
Google Scholar
Abstract
1 The influence of the hormonal condition of rats on the responsiveness of their seminal vesicles to drugs was investigated by determining pD2 and α values for adrenaline, for noradrenaline, for acetylcholine and for acetyl-β-methyl-choline on isolated vesicles of normal, of castrated, and of oestradiol-treated castrated rats. 2 pD2 values of adrenaline, of noradrenaline, of acetylcholine and of acetyl-β-methylcholine acting on seminal vesicles of castrated or of oestradiol-treated castrated rats were greater than the corresponding values obtained on the organs of normal rats. The differences were significant at the level P < 0.001. 3 Similar results were obtained for the relative intrinsic activity of noradrenaline and acetyl-β-methylcholine. 4 Consequently affinity of adrenaline, noradrenaline, acetylcholine and of acetyl-β-methylcholine for their corresponding receptors and the stimulus produced by each unit of the noradrenaline-receptor or acetyl-β-methylcholine-receptor complex were enhanced. 5 The data indicate that an increase in the sensitivity of the smooth musculature of seminal vesicles to adrenaline and noradrenaline as well as to acetylcholine and acetyl-β-methylcholine is obtained by castration, or by treatment with oestradiol following castration.