Effect of acute uremia on triglyceride kinetics in the rat

Plasma triglyceride (TG) levesl were elevated 24 hr after the production of acute uremia in rats. The effect of acute uremia on TG production rate was estimated by determining the rate of TG accumulation following Triton WR 1339 inhibition of lipoprotein removal, by measuring hepatic TG secretion rate during in situ liver perfusion, and by quantifying hepatocyte very low density lipoprotein content with the electron microscope. The results of all three of these approaches indicated that TG synthesis and secretion were decreased in acute uremia, suggesting that the associated increase in plasma TG levels had to result from a removal defect. This hypothesis was tested directly by injecting pre-labeled very low density lipoprotein TG into acutely uremic and control rats, and measuring its rate of disappearance from plasma. The t1/2 of removal in acutely uremic rats was found to be approximately twice that of control, confirming the hypothesis that the rise in plasma TG levels in acute uremia is due to a defect in removal of TG from plasma.