Nutritional Articles

Effects of exercise and glucose administration on content of insulin-sensitive glucose transporter in equine skeletal muscle.

Published: 2004-04-15

Effects of exercise and glucose administration on content of insulin-sensitive glucose transporter in equine skeletal muscle.
Movement of glucose accross plasma membranes into muscle cells is the rate-limiting step in glucose use. Movement of glucose from the blood accross the muscle sarcolemma is primarily by fascilitated diffusion via a family of structurally related proteins, the glucose transporters (GLUTs; i.e. GLUT-1 to GLUT-8). The objective of this study was to characterize insulin-sensitive glucose-transporter (GLUT4) protein in equine tissues and determine effects of exercise and glucose administration on content of GLUT-4 protein in equine skeletal muscle. In a crossover, randomized study, horses were strenuously exercised for 3 consecutive days and then administered 13.5% glucose or isotonic saline (0.9% NaCl; control) solution, IV, at similar infusion rates for 12.1 h. Samples were collected from the middle gluteal muscle before and after exercise and 10.1 h after completion of an infusion and used for measurements of glycogen concentration and total content of GLUT-4 protein. The authors concluded that GLUT-4 protein was expresed in equine skeletal and cardiac muscles. GLUT-4 protein was expressed in equine skeletal and cardiac muscles. Exercise increased total content of GLUT-4 protein in skeletal muscle, and replenishment of muscle glycogen stores after glucose infusion attenuated the exercise-induced increase in the content of GLUT-4 protein in equine skeletal muscle.

Reference
Lacombe, V.A., Hinchcliff, K.W. and Devor, S.T..2003. Effects of exercise and glucose administration on content of insulin-sensitive glucose transporter in equine skeletal muscle. American Journal of Veterinary-Research 64: 1500-1506.

Website and Publisher
http://www.avma.org/publications/ajvr/ajvrifa.asp