Effect of disuse atrophy on pectoralis muscle and blood in the pigeon

¹ Division of Animal Physiology, Department of Zoology, The Maharaja Sayajirao University, Baroda, India

Disuse atrophy in the breast muscle of the pigeon was induced by applying a plaster cast on the wings, which were kept in a dorsally extended position. Lipolytic activity in the breast muscle and blood serum was determined at different intervals from 1 day to 2 months. A higher enzyme activity in the muscle and a corresponding fall in the enzyme activity in blood serum were observed during the 1st week of atrophy. Fat and water contents in the muscle were also estimated. During the first 2 weeks there was an increase in water content of the muscle. A sudden increase in fat content was observed on the 1st day of atrophy. Later the fat content gradually decreased, and by the end of 2 months the fat content was found to be less than that in the normal pigeon. The physiological significance of such changes in lipase activity and fat content is discussed.