High-fat feeding alters the response of rat PDH complex to acute changes in glucose and insulin

• Published in: The American journal of physiology Vol. 268; no. 4; p. E752
• Main Authors: Bryson, J.M. (Royal Prince Alfred Hospital, Sydney, New South Wales, Australia.), Cooney, G.J, Wensley, V.R, Phuyal, J.L, Hew, M, Denyer, G.S, Caterson, I.D
• Format: Journal Article
• Language: English
• Published: United States 01.04.1995
• Subjects: ACIDE GRAS; ACIDOS GRASOS; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Animals; AZUCAR EN SANGRE; Blood Glucose - metabolism; Body Weight - drug effects; CORPS GRAS; DIETA; Dietary Fats - pharmacology; Eating; Fatty Acids, Nonesterified - blood; GLUCOSA; GLUCOSE; Glucose - pharmacology; GRASAS; Injections, Intravenous; Insulin - blood; INSULINA; INSULINE; Male; OXIDORREDUCTASAS; OXYDOREDUCTASE; Pyruvate Dehydrogenase Complex - metabolism; RAT; RATA; Rats; Rats, Wistar; REGIME ALIMENTAIRE; SUCRE DU SANG; TEJIDOS ANIMALES; TISSU ANIMAL; Tissue Distribution; Triglycerides - blood
• ISSN: 0002-9513; 2163-5773
• DOI: 10.1152/ajpendo.1995.268.4.E752

The activity of the pyruvate dehydrogenase complex (PDHC) was studied in tissues of controls and insulin-resistant fat-fed rats (FFR) both in the fed state and in overnight fasted animals after the induction of short-term changes in plasma insulin by an intravenous glucose load. Significant responses by the PDHC to the glucose challenge were seen in heart and white adipose tissue (WAT) in controls with smaller changes in brown adipose tissue (BAT) and quadriceps muscle (QM) and no change in liver. Reduced PDHC responses and lower fed values were seen in heart and BAT of FFR. The response in WAT of FFR was prolonged with no change in the PDHC response in QM. Plasma nonesterified fatty acids (NEFA) were decreased in response to the glucose load with no differences between controls and FFR. Tissue triglyceride levels were higher in liver and QM but not heart of FFR. These results show differential tissue PDHC responses to short-term changes in plasma insulin. The decreased PDHC activity in some tissues of the fat-fed animals despite the lack of change in plasma NEFA, together with the triglyceride accumulation seen in some tissues but not others, suggests that local intracellular fatty acid metabolism is important in the regulation of intracellular glucose oxidation