Arachidonic acid metabolism in the platelets and neutrophils of diabetic rabbit and human subjects

An alteration of arachidonic acid metabolism to prostaglandins and leukotrienes from platelets and polymorphonuclear leukocytes respectively is evident in subjects with diabetes mellitus. There is evidence of altered platelet/vascular wall interactions in diabetes mellitus and evidence that polymorphonuclear leukocytes influence the vascular walls. Theories on the pathogenesis of atherosclerosis include both blood cells. Platelet hypersensitivity is evident in those platelets from the alloxan-induced diabetic rabbit either suspended in plasma or buffer. Arachidonic acid- and collagen-induced platelet aggregation, release of 14serotonin, and T x B2 and 12-HETE production is enhanced when responses of diabetic platelets are compared to control platelets. Control rabbit neutrophils produce more LTB4, LTB4 isomers and 5-HETE than diabetic rabbits neutrophils. Decreased synthesis from diabetic rabbit neutrophils is not explained by increased catabolism of LTB4, reesterification of 5-HETE, or increased eicosanoid formation. These experiments demonstrate both platelet and neutrophil dysfunction in diabetic subjects. Because of the involvement of these cells in regulating circulatory homeostatis, abnormal behavior could aggravate the atherosclerotic process. Platelet and neutrophil dysfunctions are noted before macroscopic vascular lesions are apparent suggesting an important role in the pathogenesis of atherosclerosis