title: [Effect of heat exposure in the second trimester of pregnancy on intrauterine growth of fatal rat and the expression of HSP70, Bax and Bcl-2 of placenta].
abstract: To investigate the effect of heat exposure during the second week of pregnancy on placental development and intrauterine growth of fetal rats.
  
  
  
  24 pregnant rats were either exposed or not to a temperature of 35∓1 degrees celsius; during the second week of pregnancy. The body weight gain of the pregnant rats was measured regularly, and in late pregnancy, the pregnant rats were dissected and the number, weight, length, tail length, appearance of the offspring rats, number of live and still births, and the placental weight were recorded. The expressions of HSP70, Bax and Bcl-2 in the placenta were determined.
  
  
  
  Compared with the control group, the pregnant rats in heat exposure group had significantly lower body weight at the end of pregnancy and gestational weight gain, and the body weight, body length and tail length of the offspring rats were also significantly lower or smaller (P<0.05). The placental weight was comparable between the two groups. The placental expressions of HSP70,Bax,and Bcl-2 were significantly higher in the heat exposure group than in the control group (P<0.05).
  
  
  
  Heat exposure during the second trimester of pregnancy has adverse effects on placental development and intrauterine growth of the fetal rats by inducing heat shock response of placental tissue and apoptosis of the placental cells.
authors.affiliation: Medical College of Nanchang University, Nanchang 330006, China.E-mail: pengyb653@sina.com.
authors.forename: Yong-Bao
authors.initials: YB
authors.lastname: Peng
authors.forename: Shu-Hui
authors.initials: SH
authors.lastname: Huang
authors.forename: Jun-Ming
authors.initials: JM
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Luo
authors.forename: Qun
authors.initials: Q
authors.lastname: Zhou
authors.forename: Huai
authors.initials: H
authors.lastname: Liu
mesh_terms: D000818:Animals; D005260:Female; D047109:Fetal Development / Q000502:physiology*; D005333:Fetus; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism*; D006358:Hot Temperature / Q000009:adverse effects*; D010920:Placenta / Q000378:metabolism*; D010929:Placentation; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000378:metabolism*; D051381:Rats; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: C494828:Bax protein, rat; D050884:HSP72 Heat-Shock Proteins; D051028:bcl-2-Associated X Protein