Zinc deficiency affects neither platelet arachidonic acid metabolism nor platelet aggregation in rats

The effects of zinc deficiency on arachidonic acid (AA) metabolism and platelet aggregation were studied in rats. Concentrations of AA metabolites synthesized by collagen-stimulated platelets were greater in rats fed a zinc-deficient diet (ZD group) than pair-fed control rats (PF group). This difference appeared to be due to increased platelet number in the ZD group. Preincubation of platelet-rich plasma of ZD group with various concentrations of zinc sulfate, prior to the aggregation induced by collagen suspension, Affected neither concentrations of AA metabolites nor the degree of platelet aggregation. Contrary to a report by other investigators, ADP-induced platelet aggregation was not impaired in rats fed the zinc-deficient diet for 1 week or 5 days as compared to the pair-fed controls. Secondary phase aggregation was not observed during ADP-induced platelet aggregation regardless of concentrations of ADP, types and concentrations of anticoagulants used, routes of blood collection or types of dietary protein in this study. These results indicated that zinc deficiency does not seem to affect arachidonic acid metabolism or platelet aggregation in rats in relatively short-term studies.