STARVATION-REALIMENTATION OVERSHOOT IN GLYCEROPHOSPHATE ACYLTRANSFERASE IN ADIPOSE-TISSUE AND LIVER OF RATS IS INFLUENCED BY TYPE OF DIETARY-FAT

The purpose of this study was to determine effects of dietary fat sour ce on changes in glycerophosphate acyltransferase that occur with star vation-realimentation. Forty male Sprague-Dawley rats were randomly as signed to dietary treatments at 209 +/- 3 g of body weight. Ten rats e ach were assigned to a 65 g/100 g sucrose diet that contained 5 g/100 g fat from the following sources: stearate (42% stearate, 41% oleate); oleate (high-oleate safflower oil); palm oil; or beef tallow. Five ra ts received free access to their diet for 4 days and five rats were st arved for 2 days and then fed for 2 days. Rats were then killed and li ver and epididymal adipose tissue dissected and homogenized for glycer ophosphate acyltransferase assay. The starvation-realimentation regime n on the stearate diet stimulated adipose tissue glycerophosphate acyl transferase above non-starved controls. Realimentation on high-oleate and high-palmitate diets stimulated liver glycerophosphate acyltransfe rase most as well as produced a starvation-realimentation overshoot in steady-state glycerolipid production. Results indicate that ad libitu m consumption of diets diets containing high proportions of stearate a fter a period of starvation could overshoot liver glycerophosphate acy ltransferase to a lesser extent than if the diet contained low proport ions of this fatty acid. Diet fatty acid composition had less impact o n adipose tissue than liver glycerophosphate acyltransferase activity in rats subjected to starvation-realimentation.