Changes in rabbit platelet alpha and beta adrenoceptor number and platelet aggregation.
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.
D000818:Animals; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D004837:Epinephrine / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D010643:Phenoxybenzamine / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D011817:Rabbits; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*
D004967:Estrogens; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D010643:Phenoxybenzamine; D004837:Epinephrine