不同n-6/n-3多不饱和脂肪酸构成比对高脂饲料喂养大鼠脂联素和糖脂代谢及抗氧化能力的影响

目的探讨高脂饲料喂养条件下,不同n-6/n-3多不饱和脂肪酸(polyunsaturated fatty acid,PUFA)构成比对大鼠脂联素和糖脂代谢及抗氧化能力的影响。方法50只雄性Wistar大鼠按体重随机分为5组:1个普通饲料组(脂肪供能比17%,n-6/n-3PUFA=5∶1)和4个高脂饲料组(脂肪供能比均为42%,n-6/n-3 PUFA构成比分别为1∶1、5∶1、10∶1、20∶1)。喂养12周后检测大鼠血糖和血脂(0、4、8和12周)、血清抗氧化指标(0和12周)以及睾周脂肪组织脂联素mRNA、蛋白表达和血清脂联素水平(12周)。结果大鼠各指标初始值组间差异均无统计学意义(P>0.05)。12周时,n-6/n-3PUFA 10∶1、20∶1组血糖显著高于对照组(P<0.05),4个高脂组血清总胆固醇(total cholesterol,TC)、甘油三酯(triglyceride,TG)显著高于对照组(P<0.01),其中20∶1组TG显著高于其余3组(P<0.01);4个高脂组谷胱甘肽过氧化物酶和超氧化物歧化酶含量显著低于对照组(P<0.05),其中20∶1组下降最明显,丙二醛含量显著高于对照组(P<0.05),其中10∶1组上升最明显;20∶1组脂联素mRNA表达显著低于对照组、1∶1组和5∶1组(P<0.05),5∶1组脂联素蛋白表达水平显著高于其余高脂组(P<0.05),而20∶1组表达水平最低(P<0.05)。结论较低的n-6/n-3 PUFA构成比(1∶1和5∶1),有助于改善高脂饲料条件下大鼠糖脂代谢及抗氧化能力,提高脂联素表达。

Effects of different ratios of n-6/n-3 polyunsaturated fatty acid on adiponectin,glycolipid metabolism and antioxidant capacity in high fat-diet fed rats

OBJECTIVE To investigate effects of different ratios of n-6/n-3 Polyunsaturated fatty acid(PUFA) on adiponectin, glycolipid metabolism and antioxidant capacity in high fat-diet fed rats. METHODS Fixty male Wistar rats were randomly divided into control group(CON, 17% energy from fat, n-6/n-3 PUFA=5∶1) and high-fat treatment groups(1∶1 group∶n-6/n-3 PUFA=1∶1, 5∶1 group, n-6/n-3 PUFA=5∶1, 10∶1 group∶ n-6/n-3 PUFA=10∶1 and 20∶1 group∶ n-6/n-3 PUFA=20∶1, 42% energy from fat). Rats were fed for 12 week. Serum glucose and lipid(0, 4, 8 and 12 week) were detected. Antioxidant indexes(0 and 12 week), adiponectin mRNA and protein expressions in epididymal adipose tissues as well as serum adiponectin(12 week) were measured. RESULTS Baseline data showed no significant inter-group difference(P>0.05). 1∶1 and 5∶1 showed no significant changes in serum glucose compared with control at all time points(P>0.05), while 10∶1 and 20∶1 significantly increased it at the 12 th week(P<0.05). At the 12 th week, total cholesterol(TC) and triglycerides(TG) in high-fat treatment groups were significantly higher than control(P<0.01), with 20∶1 showing significant increment of TG compared with other high-fat treatment groups(P<0.01). At the 12th week, glutathione peroxidase and superoxide dismutase content in high-fat treatment groups all decreased significantly compared with control(P<0.05), and 20∶1 decreased most. Malondialdehyde content significantly increased in high-fat treatment groups(P<0.05), and 10∶1 increased most. Adiponectin mRNA expression significantly decreased in 20∶1 compared with control, 1∶1 and 5∶1(P<0.05). Increment of adiponectin protein expression was significantly shown in 5∶1 compared with other high-fat treatment groups(P<0.05), while it was most obviously decreased in 20∶1(P<0.05). CONCLUSION Lower n-6/n-3 PUFA ratios(1∶1 and 5∶1) contributed to improvement of glycolipid metabolism and antioxidant capacity as well as increment of adiponectin expression of rats fed with high-fat diet.