Effects of experimental diabetes on the essential fatty acid-deficient rat.

An evaluation of the EFAD syndrome in rats rendered diabetic with either alloxan or streptozotocin was performed. Diabetic rats fed an EFA-deficient diet for 7 or 13 weeks were less severely EFA-deficient than were nondiabetic rats fed EFA-deficient diet, as judged by dermal symptoms or by biochemical parameters such as the ratio of 20:3 omega 9/20:4 omega 6 (T/T ratio) and total fatty acids derived from linoleic acid. The T/T ratios of liver PL of diabetic EFA-deficient rats were lower than those of deficient control rats, and the ratios varied inversely with the blood glucose concentrations. The product/precursor ratios, arachidonic acid/linoleic acid, in liver PL were higher in diabetic deficient rats than in deficient control rats. Analysis of liver and heart PLs revealed higher arachidonic acid levels in the diabetic deficient rats than in the EFA-deficient controls, perhaps because of different growth rates. The activities of the delta 5, delta 6, and delta 9 desaturases were evaluated in liver microsomal systems. The delta 9 desaturase was depressed in diabetic rats in agreement with literature reports. The delta 6 desaturase, however, was slightly increased. The relative levels of delta 5, delta 6 and delta 9 desaturation products in liver and heart PLs did not parallel the measured desaturase activities of liver microsomes.