The effect of starvation, phloridzin, thyroid, adrenaline, insulin and pituitrin on the distribution of glycogen in the rat

Abstract

From rats killed by decapitation, desired tissues were quickly excised and the glycogen content determined according to Pfluger. The sugar in the glycogen hydrolysate was estimated by MacLean''s method. Precipitating the liver glycogen with 80% alcohol gave higher reduction values than when 66% alcohol was used; the absolute difference was independent of the glycogen content. In rats starved for 24 and 48 hrs. figures of previous investigators for glycogen of liver and muscles were confirmed. The glycogen content of heart, kidney and stomach was the same in rats fasted for 4, 24 and 48 hrs. Phlorhizin injected in rats fasted for 24 or 48 hrs. lowered the gly- cogen content of liver and muscle. Rats fed thyroid for some days and killed 4 hrs. after the last feeding contained less liver- and more muscle-glycogen than controls. When killed after 24 hrs. starvation these animals contained less glycogen in all tissues than the controls. 0.05 mgm. adrenalin per 100 gm. body weight injected in rats fasted for 24 hrs. slightly increased their liver and markedly decreased their muscle glycogen; the rats were killed 2 hrs. after injection. Insulin injected in rats fasted for 24 hrs. lowered their muscle glycogen. Injection of pituitrin had no effect on the glycogen stores.