摘要
低温是影响我国北方地区养猪业效益的因素之一,导致猪只生产性能下降,仔猪病死率升高,严重制约着我国养猪业的高效发展.本研究旨在解析低温对合作猪(Sus scrofa)肝脏抗氧化能力和脂质代谢的影响.选用75日龄健康合作猪,常温饲养7 d后随机分为低温组(CH)和常温对照组(NH).低温组在装有温度控制装置的室内(-15±2)℃饲养,常温对照组在室内常温(23±2)℃饲养,共处理15 d.分别于处理后的0、5、10、15d空腹前腔静脉采集供试猪血液,第15天屠宰采集肝脏组织,采用ELISA检测血清抗氧化指标、肝脏脂质代谢物;qPCR检测脂质代谢相关基因的表达.结果显示,随低温处理时间延长,合作猪血清总抗氧化能力(total antioxidant capacity,T-AOC)和丙二醛(malondialdehyde,MDA)含量呈先增加后降低趋势,T-AOC活性在10 d时达最高值1.94,显著高于其他处理时间(P＜0.05),MDA活性在第5天最高,极显著高于第10和15天(P＜0.01);血清超氧化物歧化酶(superoxide dismutase,SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)、过氧化氢酶(catalase,CAT)活性均呈增加趋势,其中SOD在低温处理10 d时极显著升高(P＜0.01),GSH-Px和CAT活性在低温处理5 d时活性极显著升高(P＜0.01).与常温对照组相比,低温组合作猪肝脏氧化损伤标志物蛋白质羰基(protein carbonyl,PCO)和8-羟基脱氧鸟苷(8-hydroxy-2deoxyguanosine,8-OHdG)含量极显著升高(P＜0.01);低温组合作猪肝脏脂代谢相关酶中脂肪酸合成酶(fatty acid synthase,FAS)和乙酰辅酶 A羧化酶(acetyl CoA carboxylase,ACC)活性显著降低(P＜0.05),脂蛋白 脂酶(lipoprotein lipase,LPL)、肝脂酶(hepaticlipase,HL)、谷丙转氨酶(alanine aminotransferase,ALT)、硬脂酰辅酶 A去饱和酶 1(stearoyl-CoA desaturase 1,SCD1)活性均极显著降低(P＜0.01);肉碱棕榈酰转移酶(carnitine palmitoyltransferase enzyme,CPT)活性极显著升高(P＜0.01);低温组合作猪血清甘油三酯(triglyceride,TG)含量在5 d时最高,为0.82,15 d时显著降低至0.61(P＜0.05);肝脏脂代谢相关基因胆固醇调节元件结合蛋白1c(sterol regulatory element-binding protein-1c,SREBP-1c)和过氧化物酶体增殖物激活受体α(peroxisome proliferators-activated receptors α,PPARα)的表达量显著降低(P＜0.05),p300/CBP相关因子(p300/CBP associated factor,PCAF)的表达量极显著增加(P＜0.01).综上所述,低温会造成合作猪肝脏氧化损伤,处于寒冷环境时合作猪能够通过增强肝脏脂质代谢提高其寒冷适应性.本研究为进一步探索合作猪抗寒性状形成的机制提供了参考依据.
Abstract
Low temperature is one of the factors affecting the efficiency of pig production in the northern region of China,which leads to the decline of pig production performance and the increase of piglet disease and death rate,and seriously restricts the efficient development of China's pig industry.The aim of this study was to analyzing the effects of low temperature on liver antioxidant capacity and lipid metabolism in Hezuo pigs(Sus scrofa).75-day-old healthy Hezuo pigs were selected and randomly divided into low-temperature group(CH)and normothermic control group(NH)after 7 d of room temperature rearing.The CH was reared in a room equipped with a temperature control device(-15±2)℃,and the NH was reared in a room at temperature(23±2)℃.The precess period was 15 d.Blood was collected from fasting anterior vena cava on the 0,5,10,and 15 d of the precess period,and liver tissues were collected from slaughter on the 15 d;serum antioxidant indexes and hepatic lipid metabolites were detected by ELISA,and lipid metabolism-related genes were detected by qPCR.The results showed that with the prolongation of low temperature treatment time,the serum total antioxidant capacity(T-AOC)and malondialdehyde(MDA)content of Hezuo pigs showed a trend of increasing and then decreasing,and the T-AOC activity reached the highest value of 1.94 on 10 d,which was significantly higher than the other treatment(P＜0.05),and the MDA activity was the highest on 5 d,which was significant higher than the 10 and 15 d(P＜0.05),The activities of serum superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and catalase(CAT)showed an increasing trend,in which SOD was extremely significant(P＜0.01)after 10 d of low temperature treatment,GSH-Px and CAT activities were extremely significant(P＜0.01)after 5 d of low temperature treatment.The contents of protein carbonyl(PCO)and 8-hydroxy-2deoxyguanosine(8-OHdG),markers of oxidative damage in pig livers,were extremely significantly elevated(P＜0.01)in the CH compared with the NH.The activities of fatty acid synthase(FAS)and acetyl CoA carboxylase(ACC),the enzymes related to lipid metabolism,were significantly reduced(P＜0.05)in pig livers exposed to low temperature.The activities of lipoprotein lipase(LPL),hepaticlipase(HL),alanine aminotransferase(ALT),and stearoyl-CoA desaturase 1(SCD1)were all significantly reduced(P＜0.01);carnitine palmitoyltransferase enzyme(CPT)activity was extremely significantly elevated(P＜0.01).The serum triglyceride(TG)content of the low-temperature Hezuo pigs was the highest at 0.82 on 5 d,and significantly decreased to 0.61 on 15 d(P＜0.05).The expression of hepatic lipid metabolism-related genes sterol regulatory element-binding protein-lc(SREBP-1c)and peroxisome proliferators-activated receptors α(PPARα)was significantly reduced(P＜0.05),and p300/CBP associated factor(PCAF)expression was extremely significantly increased(P＜0.01).In summary,the low temperature caused oxidative damage to the liver of Hezuo pigs,and Hezuo pigs could improve their cold adaptation by enhancing hepatic lipid metabolism when they were in a cold environment.This study provides a reference basis for further exploring the mechanism of the formation of cold-resistant traits in Hezuo pigs.
基金项目
国家自然科学基金区域创新发展联合基金(U22A20507)
国家科技期刊平台
NSTL
万方数据