Effect of Lysine -Limited Diets Containing Different Levels of L -Carnitine on Body Weight and Lipid Metabolism in Obesity -Induced Adult Rats

Kim, Ja Kyung; Kim, Mi Kyung

Abstract

This study was performed to investigate the effect of lysine-limited diets containing different levels of L-carnitine on body weight and lipid metabolism in obesity-induced adult rats. Eight-month-old male Sprague-Dawley rats (n =90 ) were raised for one month with high fat diet (40% fat as calorie )to induce obesity. After induction of obesity, rats wei-ghing 739.5 g were randomly blocked into three groups according to the body weight and raised for eight weeks with control diet (Co ), 50% lysine-limited diet (-L ), 50% lysine limitation with 0.3% pivalate diet (-L +P ). Each of three groups was allotted to 0.0% L-carnitine (0.0% CT ), 0.5% L-carnitine (0.5% CT )and 2.5% L-carnitine (2.5% CT ) groups, respectively. The levels of AST, ALT, total protein and albumin in plasma were within the normal range. Daily food intake and calorie intake tended to be lower in 2.5% CT groups than those of other groups regardless lysine limi-tation or pivalate intake. And body weight gain and calorie efficiency ratio (weight gain (g )/calorie intake (100 kcal )) were significantly the lowest in 2.5% CT groups among all experimental groups regardless of lysine limitation or pivalate intake. The weights of perirenal, epididymal fat pads and brown adipose tissue in 2.5% CT groups were significantly lower than 0.0% CT groups. Plasma total lipid, triglyceride, total cholesterol concentrations in all groups were not significant by experimental compound. HDL-cholesterol concentrations in -L +P +2.5% CT group were highest in -L +P groups. Levels of hepatic total lipid, triglyceride and total cholesterol in 2.5% CT groups were tend to be lower those than in 0.0% CT groups regardless of dietary lysine limitation and pivalate intake. Fecal total lipid excretions of 2.5% CT groups were significantly lower than in 0.0% CT groups in all experimental groups. But fecal triglyceride excretions of 2.5% CT groups were significantly higher than 0.0% CT groups regardless of lysine limitation and pivalate. In conclusion, there was no difference on body weight and lipid metabolism by dietary lysine limitation and pivalate intake. And feeding of 2.5% L-carnitine was more effective than feeding of 0.5% L-carnitine and 0.0% L-carnitine in reduction of body weight, body fat and lipid metabolism.