Diabetic patients have high susceptibility to microvascular complications and atherosclerosis. Hyperaggregability and hyperadhesiveness of platelets and decreased prostacyclin (PGI2) production in vessel walls may play an important role in those vascular disorders.
In this paper aortic PGI2 production, function of platelets and plasma and tissue lipoperoxide levels were investigated in an experimental system of alloxen diabetic rabbits.
Following results were obitained.
1) PGI2 production in diabetic rabbit aorta (0.14±0.02ng/mg⋅wet weight) was significantly decreased compared with that in controls (0.32±0.10ng/mg⋅wet weight). Treatment of the diabetic animals with insulin for 10 days restored the PGI2 production to normal level.
2) Hypersensitivity to ADP, increased MDA formation and decreased sensitivity to PGI2 were observed in diabetic rabbits platelets. Treatment of the animal with insulin restored the platelet MDA formation to normal levels.
3) Plasma and liver lipoperoxide levels were elevated in diabetic rabbits and normalized by insulin treatment.
These results suggest that lipoperoxides overproduced in diabetic organ like liver may inhibit PGI2 synthesis in vessel walls and in turn cause hyperreactivity of platelets resulting in the diabetic angiopathy.
