Changes in Adipose Tissue and Heart Lipoprotein Lipase Activities and in Serum Glucose, Insulin and Corticosterone Concentrations in Rats Adapted to a Daily Meal

Abstract

Rats trained to a daily meal (09.00 h - 11.00 h) were killed in batches every two hours over a period of 24 hours. Lipoprotein lipase activities were estimated in fresh homogenates of heart and epididymal adipose tissue. Serum glucose, insulin and corticosterone concentrations were determined.

The adipose tissue lipoprotein lipase activity and the serum concentration of glucose and insulin increased from 09.00 h to 11.00 h and decreased between 15.00 h and 17.00 h. The increase in insulin concentration at 03.00 h did not evoke any definite variation of the enzyme activity. This lack of response was tentatively attributed to high levels of circulating corticosterone.

Both the heart lipoprotein lipase activities and the serum corticosterone concentrations decreased after the meal to a minimum at 15.00 h and increased again thereafter.

Meal-Feeding - Adipose Tissue - Heart - Lipoprotein Lipase - Insulin - Corticosterone