Open AccessSex Difference in the Effect of Aspirin on Rat Platelet Aggregation and Arachidonic Acid Metabolism
Author(s) -
Masako Morikawa,
Takashi Kojima,
Michiko Inoue,
Masahiro Tsuboi
Publication year - 1985
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.37.317
Subject(s) - aspirin , cyclooxygenase , platelet , arachidonic acid , malondialdehyde , endocrinology , chemistry , castration , medicine , pharmacology , biochemistry , enzyme , oxidative stress , hormone
The rat platelet aggregation induced by collagen was stronger in males than in females. The platelet malondialdehyde (MDA) production was more in males than in females, and the platelet cyclooxygenase activity was higher in males than in females. Aspirin at a dose of 10 mg/kg inhibited the collagen-induced aggregation in males, but not in females. Aspirin at a dose of 5 mg/kg blocked the MDA production only in males, but aspirin at a dose of 10 mg/kg inhibited the MDA production in both sexes. The effect of aspirin on the cyclooxygenase activity was only in males, but aspirin at a dose of 10 mg/kg inhibited the MDA production in both sexes. The effect of aspirin on the cyclooxygenase activity was similar to that on the MDA production. In gonadectomized rats, the MDA production and the cyclooxygenase activity were decreased by castration, and they were increased by ovariectomy. Aspirin at a dose of 5 mg/kg failed to inhibit them in castrated rats. Besides, in in vitro experiments, aspirin also inhibited the MDA production and the aggregation. Nevertheless, there was no sex difference in the content of arachidonic acid, a substrate of platelet cyclooxygenase. It is suggested that there is a sex difference in rat platelet cyclooxygenase activity, and it is closely related to the sex difference in the antiplatelet effect of aspirin.