Changes in eicosanoid synthesis in the cerebrum, cerebellum and brain stem of the diabetic rat.

The effect of streptozotocin-induced diabetes mellitus (DM) on rat brain prostanoid synthesis was assessed. Prostacyclin (PGI2) synthesis was significantly reduced in the DM animals in all 3 brain regions studied (cerebrum; cerebellum; brain stem). In contrast, the synthesis of the other 3 prostanoids assessed (PGF2 alpha; PGE2; TXA2) was not significantly altered in the DM animals. Insulin treatment reverted PGI2 synthesis towards the normal pattern. Since PGI2 is a vasodilator and the other 3 prostanoids (PGF2 alpha; PGE2; TXA2) are cerebral vasoconstrictors, these changes may be relevant to the pathogenesis of the previously reported abnormalities of cerebral blood flow and the increased incidence of cerebrovascular disease in DM.