DIFFERENTIAL CHANGES IN RELATIVE LEVELS OF ARACHIDONIC-ACID IN MAJOR PHOSPHOLIPIDS FROM RAT-TISSUES DURING THE PROGRESSION OF DIABETES

Changes in the fatty acid composition of choline glycerophospholipid ( CGP) and ethanolamine glycerophospholipid (EGP) in the liver, heart, k idney, testis, spleen, and brain of rats were examined at various stag es of streptozotocin-induced diabetes. Diabetes of prolonged duration (8 weeks) caused profound alterations in the fatty acid composition of phospholipids in these tissues, the most consistent of which were a d ecrease in the relative level of arachidonic acid and an increase in t hat of linoleic acid. Although a decrease in the relative proportion o f arachidonic acid in CGP was a common feature seen in all tissues aft er long-term diabetes, the profile of the reduction during the progres s of diabetes differed among the tissues. A rapid decrease was found i n the liver and plasma at an early stage of diabetes (7 days), while t he reductions level of arachidonic acid in CGP of the heart, kidney, a nd testis appeared at a later stage of diabetes (3 weeks). CGP from th e brain retained the normal amount of arachidonic acid over the first 4 weeks of diabetes and no consistent changes in the fatty acid compos ition of phospholipids were found during this time. A slight change in the level of arachidonic acid composition in CGP from the brain was f ound after 8 weeks of diabetes. The present study indicates that the e xtent of reduction in the levels of arachidonic acid of CGP in the tis sues examined was dependent on the duration of diabetes in every case.