Effect of gangliosides on diacylglycerol content and molecular species in nerve from diabetic rats.
The effects of ganglioside treatment on 1,2-diacylglycerol content and on molecular species in 1,2-diacylglycerol, phosphatidic acid and total diacylglycerolipids, as well as Na+,K(+)-ATPase activity, were examined in sciatic nerves from streptozotocin-induced diabetic rats. Beginning 2 weeks after induction of diabetes, animals were administered mixed bovine brain gangliosides, AGF1, an inner ester derivative of this mixture, or saline for 5 weeks. The levels of 1,2-diacylglycerol and arachidonoyl-containing molecular species in age-matched non-diabetic animals were not affected by ganglioside treatment. In nerves from saline-treated diabetic animals, 1,2-diacylglycerol levels were not reduced, but both Na+,K(+)-ATPase activity and all arachidonyl-containing species except for 18:0/20:4 1,2-diacylglycerol were significantly decreased. The content of 1,2-diacylglycerol was lowered by 23 and 16% in bovine brain ganglioside and AGF1-treated diabetic animals, respectively, and the quantity of 18:0/20:4 1,2-diacylglycerol was also selectively reduced. Ganglioside administration did not affect the diminished levels of arachidonoyl-containing molecular species in 1,2-diacylglycerol, phosphatidic acid or diacylglycerolipids in nerve from diabetic rats. In the same nerves, bovine brain gangliosides partially and AGF1 completely restored Na+,K(+)-ATPase activity. The results suggest that gangliosides depress the content of total 1,2-diacylglycerol and the quantity of 18:0/20:4 1,2-diacylglycerol, specifically, in diabetic nerve. The possible relationship between the corrective action of gangliosides on Na+,K(+)-ATPase activity and the effect of these substances on 1,2-diacylglycerol molecular species composition and metabolism is discussed.
Bianchi
R
R
Mario Negri Institute for Pharmacological Research, Milan, Italy.
Zhu
X
X
Fiori
M G
MG
Eichberg
J
J
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology / Q000378:metabolism*; D004075:Diglycerides / Q000378:metabolism*; D005732:Gangliosides / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D010712:Phosphatidic Acids / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
C011439:1,2-diacylglycerol; D004075:Diglycerides; D005732:Gangliosides; D010712:Phosphatidic Acids; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase