Effect of pregnancy on the uptake of lipoprotein triglyceride fatty acids by isolated adipocytes in the rat.

Abstract

To determine whether the reduced lipoprotein lipase activity in adipose tissue in late pregnancy corresponds to parallel changes in the uptake of triglyceride fatty acids, isolated adipocytes from 19- and 21-day pregnant rats and virgin controls were incubated for different periods in the presence of rat plasma triglyceride-rich lipoproteins with their esterified fatty acids of neutral glycerides (triglycerides) labelled with 3H. The hydrolysis of triglycerides and uptake of fatty acids by the adipocytes increased linearly and parabolically with respect to the incubation time and were always lower in cells from pregnant animals than from controls. Addition of heparin to the incubation medium produced similar increases in hydrolysis and uptake in all groups. Results indicate that the diminished uptake of triglyceride fatty acids by adipose tissue contributes to hypertriglyceridemia in late pregnancy which is counteracted by lipogenesis increase tc maintain the mother's augmented body fat.