The 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.
Keywords
Platelet aggregation - Adenosine-diphosphate - Sex hormones
