| Abstract: | Treatment with phenoxybenzamine caused a decrease in the number of alpha but not beta adrenoceptor ligand binding sites on platelets from male rabbits and thus a decrease in the ratio of alpha/beta adrenoceptor number. This was accompanied by decreased aggregation both in the presence and absence of propranolol. In contrast in female rabbits maturation and oestrogen treatment resulted in a decrease in both alpha and beta adrenoceptor ligand binding and no change in the alpha/beta adrenoceptor ratio or in the aggregatory response of the platelets to adrenaline in the absence of propranolol. |
