Delayed Triglyceride Clearance from Blood in Aged Rats

Abstract

Plasma lipoprotein lipid, triglyceride clearance, and postheparin lipolytic activity were measured in young (2 months old) and aged (24 months old) male Wistar-King rats. Very low density lipoprotein and low density lipoprotein lipids (cholesterol, triglyceride, and phospholipid) and high density lipoprotein cholesterol were increased significantly in aged rats compared with the levels in young rats. Oral oil loading increased the plasma triglyceride levels to a greater extent in aged rats, and the clearance of plasma triglyceride following intravenously administered lipid occurred at a lower rate in the old rats. Lipoprotein lipase activities in post-heparin plasma and adipose tissue were higher in the young than that in the aged. These results suggest that hypertriglyceridemia in aged rats might be partly due to the delayed clearance of triglyceride by lipoprotein lipase.