Studies on the hypertriglyceridemia in the pregnant rat.

The in vivo tracer method and in vitro incorporation experiments were used to obtain information on the mechanism responsible for the hypertriglyceridemia found in 21 days pregnant rats. The results indicate that the uptake of plasma free fatty acids (FFA) by liver triglycerides of pregnant rats (2.0 mumoles FFA/min/300 g) did not differ from that of non-pregnant rats (2,1 mumoles FFA/min/300 g). The rate of liver fatty acid synthesis in pregnant rats (0,4 mumoles fatty acids/min/liver) is higher than that of non-pregnant rats (0,05 mumoles fatty acids/min/liver). In non-pregnant female and pregnant rats the turnover rates of plasma chylomicron and VLDL triglycerides were almost identical (about 2.8 mumoles triglyceride fatty acids/min/300 g, and about 2.3 mumoles triglyceride fatty acids/min/300 g, respectively). These various observations, when taken together, strongly suggest that increased hepatic triglyceride production cannot be the mechanism responsible for the hypertriglyceridemia in pregnant rats.