GnRH主动去势免疫对公猪肝脏脂肪代谢的影响

Effects of active immunization against GnRH onhepatic lipid metabolism in male pig

为研究促性腺激素释放激素(GnRH)主动免疫对公猪肝脏脂肪代谢关键基因转录水平和酶含量的影响,选用36头公猪随机分为对照组、免疫组和手术组(n=12),测定血清睾酮、甘油三酯、血糖及肝脏组织中脂肪代谢关键酶含量,实时荧光定量PCR分析肝脏组织关键基因mRNA表达变化。结果显示:GnRH主动免疫后公猪血清甘油三酯含量呈上升趋势,血清睾酮含量显著下降(P<0.05)。与对照组公猪相比,免疫去势显著提高肝脏脂肪酸合成酶(FAS)及乙酰辅酶A羧化酶(ACC)含量(P<0.05),且显著提高肝脏FAS、ACC、微粒体甘油三脂转运蛋白(MTTP)基因mRNA表达水平(P<0.05),显著下调激素敏感酯酶(HSL)与过氧化物酶体增殖物激活型受体γ(PPARγ)基因mRNA表达水平(P<0.05)。但免疫公猪血清甘油三酯含量及肝脏FAS、ACC、固醇调节元件结合蛋白-1c(SREBP-1c)mRNA表达仍显著低于手术去势公猪相应指标(P<0.05)。上述结果表明,GnRH主动免疫提高了公猪肝脏脂肪合能力,但其脂肪合成能力仍低于传统手术去势公猪。

Thirty-six male pigs were randomly allocated to three experimental groups（n=12）：immunocastrates,surgical castrates and intact controls.Serum concentrations of testosterone,triglyceride and glucose and lipid metabolism enzyme in the liver were determined.The mRNA expressions of metabolism-related genes in the liver were quantified by real-time fluorescence quantitative PCR technique.The results showed that：Active immunization against GnRH increased serum triglyceride,significantly reduced serum testosterone（P〈0.05）;Compared with intact controls,immunocastration of male pig significantly increased the capacity of fatty acid syntheses（FAS）and acetyl CoA-carboxylase（ACC）（P〈0.05）,and mRNA expression levels of FAS,ACC and microsomal triglyceride transfer protein（MTTP）（P〈0.05）;However,significantly reduced the levels of hormone sensitive lipase（HSL）and peroxisome proliferator-activated receptorγ（PPAR γ）in the liver（P〈0.05）while the serum triglyceride concentrations and hepatic FAS,ACC and sterol regulatory element binding proteins-1c（SREBP-1c）mRNA levels in immunocastrates were still significantly lower than in surgical castrates.Taken together,active immunization against GnRH improves the capacity of fat synthesis in the liver,but which is still remained at a lower level than that of surgical castrates.