动物造模 z-bio 2022-07-20 345

　　Objective: To investigate the effect of heat exposure in the second trimester on the intrauterine growth and development of rat placenta and offspring.

　　Methods: After conception, 24 healthy clean SD rats were randomly divided into control group and heat exposure group, 12 rats in each group. Rats in the control group were reared in an environment of 23 ± 1 ℃ throughout pregnancy, while rats in the heat exposure group were reared in an environment of 23 ± 1 ℃ after conception. On the 14th day of gestation, return to the environment of 23 ± 1 ℃. The body weight changes of pregnant mice at different gestational periods were measured, and fetuses were collected by caesarean section at the end of pregnancy. The number, body weight, body length, tail length, appearance, number of live/still fetuses, placental quality and placental tissue HSP70, Bax, Protein expression such as Bcl-2.

　　RESULTS: The body weight at the end of pregnancy and the increase in body weight during pregnancy in the heat exposure group were lower than those in the control group, and the differences were statistically significant (all P<0.05). Compared with the control group, the difference was statistically significant (all P<0.05); there was no significant difference in placental quality between the two groups of offspring; the expression of HSP70 (HSP70/actin) and Bax/Bcl-2 in the placenta of the heat exposure group were higher than those of the control group (all P<0.05). higher than the control group, and the difference was statistically significant (P<0.05).

　　Conclusion: Heat exposure in the second trimester can affect the growth and development of rat placenta and offspring in utero, induce the heat shock response of placental tissue and accelerate the apoptosis of placental tissue cells.