The Influence of Sex Hormones on Rat Platelet Sensitivity to Adenosine-Diphosphate

Abstract

SummaryThe sensitivity of rat platelets to the aggregating agent adenosine-diphosphate (ADP) was studied. Platelets from male and female rats demonstrated comparable sensitivity. Neither ovariectomy nor castration altered platelet sensitivity to ADP. However platelets from mock-operated female, but not mockoperated male rats were less sensitive. Administration of physiological doses of l7β-oestradiol to ovariectomised rats reduced platelet sensitivity. Administration of l7β-oestradiol to mock operated female rats increased platelet sensitivity to ADP. The results suggest that physiological amounts of oestrogen induce a loss of platelet sensitivity following surgery or stress, whereas higher concentrations of oestrogens increase platelet sensitivity.