Effects Of Intrauterine Growth Restriction During Late Pregnancy On The GrowthandDevelopment Of Perirenal Brown Adipose Tissue In Mongolia Ovine Fetus

The purpose of this experiment was to observe the effects of intrauterine growth restriction during late pregnancy on the growth and development of perirenal brown adipose tissue in mongolia ovine fetus.Eighteen ewes with singleton fetuses were allocated to three groups:restricted group 1(RG1,0.18MJ ME·kgBW-0.75·d-1,n=6),restricted group 2(RG2,0.33 MJ ME·kgBW-0.75·d-1,n=6)and a control group(CG,ad libitum,0.67 MJ ME·kgBW-0.75·d-1,n=6).The ewes were fed with nutritional restriction during the 90th to 140th day of pregnancy.At 140 days of gestation,the eweswere slaughtered.1.The increasedperirenal brown adipocytes and thedecreasedwhiteadipocyteswere observed in the restricted groups with the reduction of energy intake.The weight and growth rate of perirenaladiposetissuewere decreased in RG1 group when compared to CG,RG2 groups(P?0.05).And the total oxygen consumption rate were reduced in the RG2 and RG1 group(P?0.05).IUGR in late pregnancy affects the structure of fetal perirenal fat and thermogenesis.2.Withthenutrientssupply restriction,Myf5 protein expression was reduced in the RG1 group(P?0.05).The gene expression of CDK2 and the protein expression of CDK1,CyclinB were significantly decreased in RG2 and RG1 groups,and the protein expression of CDK4 was decreased in RG1 group(P?0.05).Inaddition,CyclinA and CyclinD protein expression showed a downward trend(P?0.05).IUGR in late pregnancy caused a decrease in the number of the BAT preadipocytes,and blocked the cell cycle progression of the fetal perirenal preadipocytes in the restricted group to varying degrees.3.With the decreasing of nutrients,the protein expression of GH wasdecreased in the RG2 group(P?0.05).In addition,the protein expression of IGF-1R decreasedin the RG1 group(P?0.05),while the expression of GHR protein in RG2 and RG1 groups showed a reducedtrend(P?0.05).And the protein expression of IGF-1,IGF-2,and IGF-2R of perirenal adipose tissue were trend of increase(P?0.05).IUGR in late pregnancy affects the normal expression of growth factors in perirenal adipose tissue.4.With the limitation of nutritional level,the protein expression of UCP1,C/EBP?reduced in restricted groups,and the protein expression of PPARydecreased in RG1 group(P?0.05).For gene experssion,the PPARy and PGC-la were reduced in RG2,RG1(P?0.05),and the UCP1?C/EBP??BMP4and BMP7 were decreased in RG1 group(P?0.05).In addition,the NRF1 proteinexpression in RG2,RG1 were greatly lower than those of CG group(P?0.05).However,there were inecreased the protein and gene expression of Leptin in RG1 group compared with the CG group(P?0.05).IUGR in late pregnancy inhibited the expression of transcription factors and adipokines in perirenal brown adipose tissue,and BAT development was blocked.