Effects of exogenous gangliosides on the pattern of respiratory enzymes in experimental diabetic retino-pathy in the rat

Abstract The prevalence of LDH1 in the retina let us think that this tissue, in normal conditions, is particularly resistant to anoxia; yet the datum relative to the variations, of LDH1 pattern in the degenerating retina with decrease of LDH1, makes more probable the hypothesis of a variable sensitivity of the enzyme in the normal metabolic conditions. This consideration, which can also be extended to the other enzymatic systems, justifies our research line. 1. a) In the retina of hyperglycemic rat by Alloxan, LDH1 presents a progressive decrease of its activity up to reach values overlapping those observed in the degenerating retina; in rats pretreated with a gangliosides mixture this change does not occur; 2. b) also the degenerating-like increase of iso-enzyme 4 is undone by pretreatment with gangliosides; 3. c) The ATPase activities of hyperglycemic rat retina are also depressed in pretreated rats with gangliosides; While the relation between ATPase (Na + − K + ) dependent activities and Mg ++ dependent activity remains depressed until 10th day of hyperglycemia, on the contrary, in the rats protected with gangliosides this relation becomes normal in 4th day; 4. d) The variations of MDH activity in the rat retina in experimental hyperglycemis do not appear statistically significant.