GnRH主动免疫对公猪体内粪臭素代谢的影响

Effects of Active Immunization against GnRH on Skatole Metabolism in Male Pigs

旨在探讨促性腺激素释放激素(Gonadotropin releasing hormone,GnRH)主动免疫对公猪体内粪臭素代谢的影响。36只公猪随机分为免疫组(10周龄时初免,18周龄加免)、手术去势组(1周龄外科阉割)及完整对照组(不作任何处理)。应用ELISA检测血清中睾酮、雌二醇及雄烯酮含量,采用高效液相色谱检测脂肪中粪臭素、雄烯酮和血液中雄烯酮含量,荧光定量PCR检测肝中粪臭素代谢相关基因mRNA表达量,ELISA检测肝中粪臭素代谢相关蛋白表达。结果显示,GnRH主动免疫后,血清睾酮浓度显著下降(P<0.05),睾丸严重萎缩。免疫组和手术组公猪血清中睾酮、雌二醇、雄烯酮浓度和脂肪中粪臭素、雄烯酮含量相似(P>0.05),均显著低于对照组(P<0.05)。免疫组公猪肝中CAR、COUP-TF1、CYP2E1、CYB5A、CYP2C49、GSTO2mRNA表达变化与手术组相似(P>0.05),均显著高于对照组(P<0.05);CYP2A19mRNA表达量手术组显著高于免疫组(P<0.05),免疫组显著高于对照组(P<0.05);而PXR、SULT1A1mRNA表达量在3组间无明显差异(P>0.05)。免疫组公猪肝中CYP2A19、CYP2C49和GSTO2蛋白表达变化与手术组相似(P>0.05),均显著高于对照组(P<0.05);CYP2E1和CYB5A蛋白表达量在手术组最高,对照组最低,免疫组介于两组之间,与两组均有显著性差异(P<0.05);而SULT1A1蛋白表达量在3组间无明显差异(P>0.05)。综上表明,GnRH主动免疫降低公猪血清中睾酮、雌二醇和雄烯酮含量,上调肝CYP450s和GSTO2基因和蛋白表达,加速粪臭素在肝中的代谢,从而降低公猪膻味。

The objective of the present study was to investigate the effects of active immunization against GnRH on skatole metabolism in boars.Thirty-six boars at the age of 10 weeks were randomly allocated to 3groups.Included intact males（not administrated）,Immuno-castrates（immunized against GnRH at 10 and 18weeks of age）,and Surgical castrates（surgically castrated at the age of one week）.The hormone levels of testosterone and estradiol in plasma were determined by ELISA,the androstenone levels in plasma and androstenone,skatole levels in fat were determined by HPLC.The mRNA expression of skatole-metabolism genes in the liver were analyzed by realtime fluorescence quantitative PCR technique,and the protein expression of them were determinedby ELISA.Active immunization against GnRH in boars resulted in a atrophy of testes and reduction of plasma testosterone levels（P〈0.05）.Plasma testosterone,androstenone,estradiol levels and fat androstenone and skatole levels in immunized boars were similar to that of surgical castrated boars（P〉0.05）,in which were significantly lower than that of intact controls（P〈0.05）.In the liver,CAR COUP-TF1,CYP2E1,CYB5 A,CYP2C49,GSTO2 mRNA expression in immunecastrated boars were similar to that of surgical castrated boars（P〉0.05）,which were significantly higher than that of intact controls（P〈0.05）;the CYP2A19 mRNA expression in surgical castrated pigs was higher than in intact controls（P〈0.05）,while CYP2A19 mRNA expression in immunized boars was in between,which was significantly different from either surgical castrates or intact controls（P〈0.05）,PXRand SULT1A1 mRNA expression were not significantly different among 3groups（P〉0.05）.In the liver,the CYP2E1,CYB5 A protein expression were highest for surgical castrated pigs and lowest for intact controls,with vaccinated pigs at an intermediate level;CYP2A19,CYP2C49,GSTO2 protein expression in surgical castrated boars were similar to that of surgical castrated boars（P〉0.05）,in which both were significantly higher than intact controls（P〈0.05）;but SULT1A1 protein expression had no significant difference among 3groups（P〉0.05）.Active immunization against GnRH in boars decreased plasma testosterone,estradiol and androstenone levels,increased CYP450 sand GSTO2mRNA and protein expression and to reduce boar-taint by accelerating skatole metabolism in the liver.