Changes of Serum Fatty Acid and Carnitine Levels after Administration of L-carnitine in Rats

Lee, Jae Won; Hong, Young Mi

Abstract

PURPOSE: Obesity is known to be associated with hypertension, dyslipidemia, and fatty liver and is thought to be associated with increased levels of free fatty acids. One of the strategies for decreasing free fatty acid levels is stimulation of hepatic lipid oxidation with L-carnitine. Carnitine is an essential cofactor for transport of long-chain fatty acid into mitochondria for oxidation. This study was designed to evaluate the changes of serum fatty acids and carnitine levels after exogenous injection of L-carnitine.
METHODS
Sprague Dawley rats were divided into two groups. Group A was control. Group B was given intraperitoneal injection with L-carnitine(200 mg/kg) daily for two weeks. Serum lipid (total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol) and fatty acid levels were analyzed on the first day of the first and second weeks after injection of L-carnitine. Total, free, and acyl carnitine levels also were performed by a enzymatic cycling techniques at the same day intervals.
RESULTS
There was no significant difference between the two groups in total cholesterol, HDL- cholesterol, LDL-cholesterol levels before and after the administration of L-carnitine. But triglyceride levels were significantly decreased at the first week in group B compared with group A. Among free fatty acids, linoleic acid showed significant decrement(A group : 131.3+/-31.3 mg/dL vs B group : 90.0+/-7.0 mg/dL) at the first week. Total, free, and acyl carnitine levels showed significant increments at all days intervals, but only free carnitine showed significant increments according to cumulative doses of carnitine.
CONCLUSION
Plasma linoleic acid, a long-chain fatty acid, showed significant decrement after administration of L-carnitine in the first week. This may suggest that L-carnitine can be used as an antilipidemic agent for obese patients. A prospective study will investigate obese children in the future.