动物造模 z-bio 2021-09-29 725

　　Objective: To investigate the effects of heat exposure in the third trimester of pregnancy on rat placenta and fetal intrauterine development.

　　Method: After conception, 24 healthy and clean SD rats were randomly divided into a control group and a heat exposure group, with 12 rats in each group. The pregnant mice in the control group were raised in an environment of 23±1°C during pregnancy, and the heat-exposed group was raised in an environment of 23±1°C after conception. The feed temperature rose to 35°C. The animals were raised at ±1°C from the 8th to the 13th day of gestation and 23±1°C on the 14th day of gestation. Measure the weight changes of pregnant mice during each pregnancy period, and perform cesarean section at the end of pregnancy to determine the number, weight, body length, tail length, appearance, number of live/dead births, and placental quality. And detect the protein expression of placenta tissue, such as HSP70, Bax, Bcl-2,

　　Result: The weight gain during the end of pregnancy and the weight gain during pregnancy in the heat exposure group was less than that of the control group, and the difference was statistically significant (both Pu003c0.05). The weight, body length and tail length of the offspring of the heat exposure group were shorter than those of the control group, and the difference was statistically significant (both Pu003c0.05). There was no statistical difference in placenta quality. The offspring of the two groups; the expression of HSP70 (HSP70/actin) and Bax/Bcl- of placenta in the heat-exposed group 2 were higher than those of the control group, and the difference was statistically significant (Pu003c0.05).

　　Conclusion: High temperature exposure in the second trimester affects the growth and development of rat placenta and its offspring, induces heat shock response in placental tissue, and accelerates placental tissue cell apoptosis.