The Impact Of The Exogenous Thyroxine On The Development Of Cerebellum In The Offspring Of Rats With Pregnancy Induced Hypertension

Objective:To investigate the effect of exogenous thyroxine on the development of the nervous system in the offspring of pregnant women with pregnancy-induced hypertension.Method:Healthy non pregnant SD female rats were selected to establish the brain injury model of maternal offspring of pregnancy induced hypertension(PIH),and the effects of exogenous thyroxine on neonatal rats were studied.The rats were randomly divided into PIH group(Group H),PIH+T group(PIH+T Group)and normal group(N Group).The pregnant rats in group H and PIH+T were injected with L-arginine(40 mg/kg)via caudal vein from 14 to 20 days after conception,and blood pressure was measured twice a day.Heart blood samples were taken from the mothers of each group 6 hours after delivery to detect the content of thyroxine.From the first day after birth(P1)to the tenth day(P10),the newborn rats in PIH+T group were injected subcutaneously with thyroxine 5 ug/kg.D.In contrast,group H and group n were injected with 0.2ml normal saline.The body weight and the content of thyroxine in blood were measured at different postnatal stages(P7,P14,p21,P28).Hematoxylin eosin staining(HE staining)was used to detect the Purkinje cells and their morphology in cerebellar cortex.The expression of BDNF protein in cerebellar cortex of newborn rats was detected by Western blotting.Results:1)Compared with group N,the blood pressure of group H and group PIH+T were significantly increased(P<0.05),and the serum thyroxine concentration was substantially decreased(P<0.05);there was no significant difference in the two targets between group H and PIH+T(P>0.05).2)The levels of thyroxine in PIH+T and N groups were significantly higher than those in H group(P<0.05),and PIH+T group was significantly lower than N group at P14 and P21(P<0.05),P28 There was no substantial difference between group N and group N(P>0.05).3)At P7,the body weight of newborn rats in group N was memorably higher than that in group H and PIH+T(P<0.05),and there was no significant difference in body weight between PIH+T group and group H(P>,0.05).At P14 and P21,the body weight of newborn rats in group N and PIH+T was significantly higher than that in group H(P<0.05),and there was no significant difference between the body weight of newborn rats in group N and PIH+T(P>0.05).At P28,the weight of newborn mice in group H was significantly higher than that in group N and PIH+T(P<0.05).4)Neatly arranged Purkinje cells can be observed in the cerebellar cortex from seventh day after birth in each group.In the cerebellum of group PIH+T and N,on the 14th day,the 21st day and the 28th day after birth,the number of Purkinje cells is higher than that in the group H,and the number of Purkinje cells in the group PIH+T is higher than that in the group N,and the arrangement is more orderly.5)The expression of BDNF in the cerebellum of the newborn rats of group H was higher than that of group PIH+T and N at 7 days after birth(P<0.05).On the 14th,21st and 28th days after birth,BDNF in the cerebellum of group PIH+T and N,the protein expression was higher than that of the group H(P<0.05).Conclusion:1.Pregnancy induced hypertension(PIH)can inhibit the secretion of thyroxine from mother to infant,cause low birth weight,reduce Purkinje cell development and BDNF protein expression;2.Timely and appropriate thyroid hormone intervention therapy can stimulate Purkinje cell development,increase the expression of BDNF protein,improve the growth and development inhibition of offspring caused by pregnancy induced hypertension,and repair the brain development disorder.