Effects of dietary different ratios of n-3 to n-6 polyunsaturated fatty acids on AMP-activated protein kinase expression of rats.

Objective To study the effects of dietary different ratios of n3/n6 polyunsaturated fatty acids(PUFA) on AMP-activated protein kinase (AMPK) expression of rats. Method According to serum total cholesterol level, male Sprague-Dawley rats were randomly divided into 6 groups, and fed common feed, high fat feed, high fat with n-3/n-6 1:1 PUFA feed, high fat with n-3/n-6 1:5 PUFA feed, common feed with n-3/n-6 1:1 PUFA diet and common feed with n-3/n-6 1:5 PUFA diet respectively. Weights were measured every 5 d, and food intakes were measured daily. We collected the blood sample at 0, 15, 30, 45 d and total cholesterol (TC) in the plasma were measured. After 45 d, the rats were sacrificed and Western blotting was used for measuring the expression of AMPK-α protein and its phosphorylation activity in liver and hypothalamus respectively. Results Four feeds with any ratio of n-3/n-6 PUFA resulted in significant decrease of body weight gain, TC in plasma, AMPK-α protein level in hypothalamus compared to high fat feeds. The AMPK-α protein level in liver increased in the four PUFA diets compared to high fat feeds. These situations in two groups with common feed were more significant than the high fat feed group. Conclusion Dietary PUFA improves lipid metabolism and decreases fat accumulation, which may be related with appetite control and fatty acid oxidation through AMPK path.