Glucagon effect on glycogen content of chicken liver and muscles

The experiments were carried out on broiler chickens divided randomly into two groups differing in the feeding level and, consequently, in the rate of weight gain. Half the chickens in each group were given a single dose of glucagon 150 micrograms/kg, and the other half received a control solution of glycine buffer. The chickens were investigated 1--1.5 hour after feeding and after 18--20 hours of starvation using the technique of biopsy of the liver and the external pectoral muscle. In the biopsy specimens the glycogen level was determined immediately before glucagon administration and 30--60--90 minutes after the injection. It was found that glucagon injection caused either a rise or a fall in the glycogen level in the liver and that the trend of these changes depended on the feeding level of the chickens and on the duration of starvation of the birds before treatment. The glycogen level in the pectoral muscle of the chickens kept on the higher feeding level was observed to fall one hour after glucagon administration.