Effects of streptozotocin-diabetes and insulin administration in vivo or in vitro on the activities of five enzymes in the adipose-tissue triacylglycerol-synthesis pathway.
At 2 days after administration of streptozotocin (100 mg/kg), activities in rat epididymal fat-pads of the following enzymes were significantly decreased: fatty acyl-CoA synthetase (FAS), mitochondrial and microsomal forms of glycerolphosphate acyltransferase (GPAT), monoacylglycerolphosphate acyltransferase (MGPAT) and Mg2+-dependent phosphatidate phosphohydrolase (PPH). There were no significant changes in diacylglycerol acyltransferase or Mg2+-independent PPH. Insulin administration to diabetic rats over 2 days restored activities of FAS, both forms of GPAT, MGPAT and Mg2+-dependent PPH. Significant restoration of all five activities was also seen 2 h after a single administration of insulin, but was not observed 45 min after insulin treatment. Insulin significantly increased all five enzyme activities when adipocytes from diabetic rats were incubated for 2 h with a mixture of glucose, lactate, pyruvate and amino acids.
Saggerson
E D
ED
Carpenter
C A
CA
D000217:Acyltransferases / Q000378:metabolism; D000273:Adipose Tissue / Q000187:drug effects / Q000201:enzymology*; D000818:Animals; D003066:Coenzyme A Ligases / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology*; D051048:Diacylglycerol O-Acyltransferase; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D010711:Phosphatidate Phosphatase / Q000378:metabolism; D051381:Rats; D014280:Triglycerides / Q000096:biosynthesis*
D007328:Insulin; D014280:Triglycerides; D000217:Acyltransferases; D005992:Glycerol-3-Phosphate O-Acyltransferase; D051048:Diacylglycerol O-Acyltransferase; D010711:Phosphatidate Phosphatase; D003066:Coenzyme A Ligases