Effects of Starvation on Glycogen Contents of Heart, Skeletal Muscle and Liver in Several Mammals

Abstract

The effects of short-term starvation on cardiac, hepatic and skeletal muscle glycogen contents were observed using kids, piglets, rats, hamsters and guinea-pigs. 1) Cardiac glycogen; In the kids given a milk-replacer once daily, it was highest at 2 hr after suckling. In the rats given a diet during the beginning of the light period, food consumption decreased it significantly (P<0.05). In rats, hamsters, guinea-pigs and piglets fed ad libitum, starvation increased it. 2) Skeletal muscle glycogen; In kids and rats adapted to the restricted feeding, food consumption increased it and starvation decreased it. In the animals fed ad libitum, 33 to 59% of glycogen were lost during starvation. The piglets of 2.5 weeks old depositted 21.4mg/g of glycogen in the feeding period. After 24hr starvation, 14.3mg/g of glycogen was stored. 3) Hepatic glycogen; In the animals with ad libitum feeding, it fell by over 90% during starvation. In kids and rats with the restricted feeding, food intake increased it. 4) Plasma free fatty acids (FFA); Starvation increased it and food ingestion decreased it significantly (P<0.05). A positive correlation between cardiac glycogen and plasma FFA was not found in the kids. 5) These results show that there is a cyclic change in the skeletal muscle and liver glycogen content, which is characterized as having a peak just after the meal and a nadir just before the meal, and that the cyclic change in cardiac glycogen seems to be affected by an alteration of feeding time.