The Effect Of Stress On Cholesterol Metabolism In Offspring Liver During Gestation Of Maternal And Its Regulation

The purpose of this study was to investigate whether the effect of heat stress on the liver biliary solid metabolism of the offspring of postpartum sows would change.The experiment was divided into three parts.The first part studied the effect of heat stress on piglets during late gestation.The second part studies the effect of heat stress on cholesterol metabolism in offspring of postpartum sows.During late gestation,SD rats were used as the research model to study the effect of DEX treatment on the development of offspring in the last week of gestation.1.Effect of heat stress on piglets in the third trimester of pregnancyThis experiment takes great 12 head changbai first-timer sows the random divided into:the control group(CON)6 sows(18 to 22℃),the heat stress group(HS)6 sows(28-32℃)single column,record the piglet birth weight,weaned weight,and so on,collect blood,liver,etc.,and statistical analysis of offspring the proportion of different organs,blood biochemical index and offspring liver triglyceride and cholesterol levels.The results showed that heat stress had no significant effect on the proportion of liver,spleen,kidney,longissimus dorsi,lumbar maximus and hippocampus in newborn male piglets.The effect of heat stress on the proportion of liver,spleen,kidney and lumbago major in weaned male piglets was not significant.The proportion of longissimus dorsi decreased significantly(P<0.01).Heat stress in the third trimester had no significant effect on serum high-density lipoprotein cholesterol(HDL-C)and total bile acid(TBA)of newborn piglets.Serum cholesterol(CHOL)and LDL-C in HS group were significantly higher than CON group(P<0.05).Heat stress in postgestation sows had no significant effect on plasma CHOL and LDL-C content of weaned piglets.HDL-C content was extremely significantly higher than that of CON group(P<0.01),and TBA content was also significantly higher than that of CON group(P<0.05).The effect of heat stress on liver cholesterol and triglyceride of newborn and weaned piglets was not obvious.The effect of liver glycogen in newborn piglets was not obvious,and the original liver glycogen in weaned piglets decreased(P=0.06).The above results showed that the sows’ heat stress in the third trimester increased the content of CHOL and LDL-C in the serum of newborn piglets.Serum HDL-C content decreased and TBA content increased in weaned piglets.There was no significant difference in liver cholesterol and triglyceride.2 Effects of heat stress on cholesterol metabolism in offspring of postpartum sowsThe purpose of this study was to investigate the effect of heat stress on the liver cholesterol metabolism of newborn and weaned piglets in the third trimester.Compared with CON group,the mRNA expression levels of CYP7A1 and FXR in the liver of newborn piglets in HS group were significantly decreased(P<0.05),and the mRNA expression levels of CYP27A1 were significantly increased(P<0.05).MRNA expression level of LDLR was significantly increased(P<0.01).The mRNA expression level of SR-B1 showed an upward trend(P=0.08).The protein expression level of HMGCR,a key enzyme for cholesterol synthesis,was significantly increased(P<0.05),but it had no effect on the protein expression level of SREBP2.Protein expression levels of CYP7A1,CYP27A1 and LXR involved in cholesterol decomposition were significantly increased(P<0.05),while protein expression levels of FXR were significantly increased(P<0.01).The expression level of SR-B1(P=0.07)was increased.The expression level of LDLR,a key protein involved in cholesterol transport,was significantly increased(P<0.05),and the expression level of GR protein was significantly increased(P<0.05).In the liver of weaned piglets,the mRNA expression level of ApoE in the HS group was significantly increased(P<0.05),and the mRNA expression level of FXR was extremely significantly increased(P<0.01).MRNA expression level of CYP8B1 was significantly decreased(P<0.05).The expression level of HMGCR protein,a key enzyme for cholesterol synthesis,was not significantly affected.The expression levels of CYP7A1(P=0.07)and CYP27A1(P=0.07),related proteins involved in cholesterol decomposition,showed an increasing trend,while the protein expression levels of LXR and FXR had no significant influence.The expression level of SR-B1,a key protein involved in cholesterol reversal,was significantly decreased(P<0.01).The protein expression level involved in cholesterol transporter uptake of LDLR was significantly decreased(P<0.01).The above results showed that heat stress in the third trimester of sows promoted the decomposition of cholesterol in the liver of newborn piglets and the expression of transportable protein.The liver of weaned piglets showed increased cholesterol breakdown,inhibited reverse transport and transport uptake,and increased bile acid synthesis.3 The effect of DEX treatment on the development of maternal and offspring during late pregnancyWill be pregnant SD rats(n=8)were randomly divided into:the control group(CON),dexamethasone treatment group,dexamethasone(DEX)+(Inulin)Inulin treatment group,on 13th day mother pregnancy will dexamethasone sodium salt(0.2 mg/kg/d)and Inulin(2 g/kg/d)is mixed with water,gestational 19 days gathering fetal rat liver and generation of rat blood,liver,placenta,weighing and record.Compared with CON group,the weight of the DEX group was significantly decreased(P<0.05),the liver-body ratio was significantly increased(P<0.05),and the content of CHOL and TG in the liver of the DEX group was significantly increased(P<0.05).There was no significant change in fetal weight,but both liver weight and liver-body ratio were significantly decreased(P<0.05).TG content in fetal liver was significantly increased(P<0.05),and CHOL content had no effect.Inulin treatment significantly increased fetal weight(P<0.05),decreased liver-body ratio(P=0.09),and decreased CHOL content in liver of Inulin group(P<0.05).Serum ALT,AST,CHOL,TG,HDL-C,and LDL-C were all significantly increased(P<0.05).After Inulin addition,the content of CHOL and HDL-C in Inulin group decreased significantly(P<0.05),while the content of LDL-C decreased(P=0.07).Effect of DEX on cholesterol metabolism in liver of female rats:there was no significant difference in the expression level of HMGCR mRNA,a key enzyme for cholesterol synthesis;protein expression level was significantly increased,and SREBP2 mRNA expression level was significantly decreased(P<0.05).The expression level of CYP7A1 mRNA,a key enzyme involved in the classical pathway of cholesterol degradation,was significantly increased,protein expression level was significantly decreased,LXR mRNA expression level was significantly reduced,and protein expression level was significantly reduced(P<0.05),but there were no significant differences in the expression level of CYP27A1 mRNA,a key enzyme in the liver cholesterol degradation replacement pathway,and protein expression level.The expression level of LDLR mRNA,a gene involved in cholesterol transport,was significantly increased,and the protein expression level showed an increasing trend(P=0.08).The expression levels of ABCG1,ABCG5,ABCG8 and ApoAl mRNA were significantly decreased(P<0.05),the expression levels of ABCA1 mRNA were decreased(P=0.07),and the expression levels of SR-B1 protein were not significantly different.Inulin treatment significantly increased HMGCR mRNA expression and decreased protein expression in Inulin group(P<0.05).The expression levels of CYP7A1 mRNA and protein were significantly increased,while there were no significant differences in the expression levels of CYP27A1 mRNA and protein.There were no significant differences in LDLR mRNA expression and protein expression levels,while ABCA1 mRNA expression level showed an increasing trend(P=0.07),LXR protein expression level significantly decreased(P<0.05),and SR-B1 protein expression level significantly increased(P<0.05).The above results showed that DEX treatment in the late gestation period of the mother rats showed that the weight of the mother rats decreased and the ratio of liver to body was increased.The contents of CHOL,HDL-C and LDL-C in serum were increased.The content of CHOL and TG in liver was increased.After inulin addition,serum CHOL,HDL-C,LDL-C and liver CHOL were reduced in the mothers.In the liver of maternal,the transport of cholesterol synthesis was increased,the decomposition was decreased,and the reverse transport was also decreased.After inulin was added,the cholesterol decomposition was increased,the synthesis was decreased,and the reverse transport level was increased.Inulin could alleviate the cholesterol increase caused by DEX stress.