Studies Of CLA Affect On Adiposity Rats And Diabetes Rats And Its Mechanisms

Conjugated linoleic acid (CLA) refers to a group of polyunsaturated fatty acids that exist as positional and geometric isomers of linoleic acid (LA; 18:2). CLA possess many physiologic properties including reduce accumulation of body fat and affect the lipid metabolism, reduce TG level and antiatherosclerosis. Besides anticarcinogenesis, CLA can improve immune function, antidiabetogenesis, antioxidant, and growth. Researchs have shown: CLA may are ligands for Peroxisome proliferator-activated receptor (PPAR), and activating PPAR. PPAR have a closed relationship with cardiovascular disease, diabetes mellitus, adiposity, tumors, and the growth and differentiation of adipocyte cells. The uncoupled proteins (UCPs) are found in the inner mitochondrial membrane and are able to affect energy metabolism. UCP family have the binding site PPRE (TGACCTTTGACCT) so it may be modulated by PPAR, PPARy can induce the expression of UCP2.Leptin is the product of the obese (OB) gene, producted in adipose tissue, existence in blood. It plays an important role in the regulation of food intake, energy expenditure and reduce body weight. Our experiment is about the effects of CLA onadiposity rats and diabetes rats, observe the changes of body weigt, serum lipids, leptin, UCP2 and PPARγ, and prove CLA can affect diposity rats and diabetes rats through modulate UCP2 and leptin excretion in adipocyte. This study will provide experimental basement for further understanding the molecul mechanisms of the relationship between obesity and diabetes. Accordingly, and it is also beneficial for us to prevent and cure adiposity and diabetes mellitus by using foods rich in CLA or medicine made of effective components of CLA. MethodsFemale Wistar rats were fed with high lipids and high sugar diet (20% lipids 20%sugar 5%yolk powde 55% common feed) for a month to make adiposity rats model, and some rats are injected with streptozoticin (STZ) to induce type II diabetes rats model, monitoring body weight changes. Groups: 1. Adiposity model rats were divided into 5 groups, (l)Low dosage(0.4g/ kg bw) (2)Middle dosage(0.8g/ kg bw) (3)High dosage(1.6g/ kg bw) (4)Obesity control. (5)Normal control. 2. Diabetes mellitus model rats were divided into 5 groups, (l)Low dosage(0.4g/ kg bw) (2)Middle dosage(0.8g/ kg bw) (3)High dosage(1.6g/ kg bw) (4)Diabetes control. (5)Normal control. After a month interference with CLA, assay the serum glucose and insulin levels with GOD-PAP and radio-immunity methods, detect leptin and UCP2 expression in adipose tissuewith western blotting, detect leptin expression in pancreas islet with immunohistochemistry method. Results1, Effect of CLA on obesity rats:(l)Body weight changes: Compared with that of control group, 3 intervention groups decrease 4.8% 6.1% 11.7%(P<0.05). CLA 1.6g/kg bw group body weight decrease significantly. (2)Serum lipids: serum triglyceride and total cholesterol levels decrease as dosage rised. (3) Leptin expression: western blotting show 0.4g/kg.bw 0.8g/kg.bw> 1.6g/kg.bw groups decrease expression of leptin 16.39% 21.26% 18.07%. (4)UCP2 expression increased as CLA dosage increased. 0.4g/kg.bw 0.8g/kg.bw , 1.6g/kg.bw groups increase...