Liver Components, Blood Glucose and Ketone Bodies in Fed and Starved Suckling Rats

Abstract

Rats of 5, 10, 20 and 30 days of age were compared with adults. In the fed state liver total fatty acids and blood ketones concentrations are high in the youngest animals and decrease throughout the suckling period. Liver citrate does not differ among the groups and the same is true for acetyl CoA with the exception of the 20 days old animals whose liver concentration is lower than in the others. Liver glycogen and blood glucose are low in the youngest rats increasing during the suckling period to attain the adult levels at the age of 20 days. After 24 h of starvation the liver total fatty acids concentration does not change in the young animals or even decreases in the rats of 20 days of age while in those of 30 days and the adults there is a significant rise. Liver acetyl CoA and blood ketones increase with fasting in all the groups while the concentration of citric acid rises in the livers from rats of 5 and 10 days of age, does not change in those of 20 days and falls in the older animals. The fall in blood glucose with fasting is less pronounced in the young rats, and it is even not shown in the animals of 20 days of age. Thus the high lipid availability in the newborn rats allows them a preservation of blood glucose which is specially seen in the fasted state. This is maximized in the rats of 20 days of age thanks to a concomitant increase in the carbohydrate intake as the animals start sampling solid food.

Key words

Suckling - Starvation - Liver Metabolism - Acetyl-CoA - Citrate