Regulation by carbohydrate and clofibric acid of palmitoyl-CoA chain elongation in the liver of rats.
Regulation of palmitoyl-CoA chain elongation (PCE) and its contribution to oleic acid formation were investigated in rat liver in comparison with stearoyl-CoA desaturase (SCD). Hepatic PCE activity was induced by the administration of 20% wt/vol glucose or fructose in the drinking water of normal rats. In streptozotocin-induced diabetic rats, the activities of both PCE and SCD were suppressed, and fructose, but not glucose, feeding caused an increase in the activities of both enzymes. Treatment of normal rats with clofibric acid in combination with carbohydrate further increased PCE, but not SCD, activity. FA analysis of hepatic lipids revealed that the proportion of oleic acid (18:1 n-9) increased upon administration of carbohydrate or clofibric acid. The treatment of rats with clofibric acid in combination with carbohydrate greatly increased the proportion of 18:1 n-9. A significant correlation was observed between PCE activity and the hepatic proportion of 18:1 n-9 (r2 = 0.874, P < 0.01), whereas the relationship between SCD activity and the proportion of 18:1 n-9 was not significant (r2 = 0.552, P > 0.05). Taken together, these results suggest that carbohydrate induces PCE as well as SCD activity to increase the hepatic 18:1 content in rat liver, and the increased PCE activity seems to be responsible for the further increase in 18:1 n-9 when carbohydrate is administered in combination with clofibric acid.
Kudo
Naomi
N
Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan. naokudo@josai.ac.jp
Toyama
Tomoaki
T
Mitsumoto
Atsushi
A
Kawashima
Yoichi
Y
D008243:1-Acylglycerophosphocholine O-Acyltransferase / Q000378:metabolism; D000123:Acetyltransferases / Q000378:metabolism; D042962:Acyl-CoA Oxidase / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002241:Carbohydrates / Q000494:pharmacology*; D002995:Clofibric Acid / Q000494:pharmacology*; D003066:Coenzyme A Ligases / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism; D004357:Drug Synergism; D000081031:Fatty Acid Elongases; D005227:Fatty Acids / Q000032:analysis; D005632:Fructose / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000097:blood; D008099:Liver / Q000737:chemistry / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D019301:Oleic Acid / Q000032:analysis / Q000096:biosynthesis; D010171:Palmitoyl Coenzyme A / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism; D000098859:Long-Chain-Fatty-Acid-CoA Ligase
D001786:Blood Glucose; D002241:Carbohydrates; D005227:Fatty Acids; D007328:Insulin; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D010171:Palmitoyl Coenzyme A; D019301:Oleic Acid; D005632:Fructose; D002995:Clofibric Acid; D013230:Stearoyl-CoA Desaturase; D042962:Acyl-CoA Oxidase; D000123:Acetyltransferases; D000081031:Fatty Acid Elongases; D008243:1-Acylglycerophosphocholine O-Acyltransferase; D003066:Coenzyme A Ligases; C090799:FAA2 protein, S cerevisiae; D000098859:Long-Chain-Fatty-Acid-CoA Ligase; D005947:Glucose