| Abstract: | To resolve the question of the magnitude of the intestine's contribution to circulating very low density lipoproteins (VLDL), measurements of intestinal, hepatic, and total VLDL--triglyceride were made on the same animals or on animals studied under comparable conditions. Animals were examined in the fasted state and during infusion of a fat-free meal. Intestinal VLDL secretion was determined through timed collections of lymph from the mesenteric lymph duct; hepatic and total VLDL secretion rates were estimated by the accumulation of plasma VLDL after injections of Triton WR 1339. Results indicate that the intestine contributes only a minor portion (11%) of the amount of triglyceride entering into the plasma compartment in the fasted state. Although intestinal triglyceride production is increased by 50% (p less than 0.01) in fed rats, the overall contribution of the intestine is not significantly altered in fed rats and represents only 14--17% of total body VLDL secretion. Thus, although intestinal VLDL secretion can be modified experimentally, its total impact on endogenous triglyceride production in normotriglyceridemic rats is small. |
