Hypertriglyceridemia in the diabetic rat. Defective removal of serum very low density

Streptozotocin-induced diabetic rats show a marked fasting hypertriglyceridemia. It appears that only the very low density lipoprotein (VLDL) fraction is increased. VLDL from either normal or diabetic rats was labelled in vivo in the triglyceride moiety with [3H]palmitate and isolated. Both preparations, if injected intravenously into recipient rats, are removed more slowly from the circulation of diabetic rats as compared to normal rats, resulting in a reduction of the fractional catabolic rate (F.C.R.) by 70%. However, the absolute catabolic rate (turnover) of VLDL triglycerides was not changed in diabetics. It is concluded that the hypertriglyceridemia of the the diabetic rat is caused by a defective removal mechanism of VLDL triglycerides. The F.C.R. of 125I-labelled low density lipoproteins and high density lipoproteins is only 1-3% of the value for VLDL triglycerides and unchanged in diabetic rats.