Effect Of Prenatal Hypoxia On The Cardiac Cell-extracellular Matrix Connections And Myocardial Remodeling In Rat Offspring

Objective: Prenatal chronic hypoxia is related to adulthood cardiovascular disease. It remains unclear how prenatal chronic hypoxia and the period of hypoxia affect local cardiac cell-extracellular matrix connections and myocardial remodeling . This article want to study in different periods of chronic hypoxia during pregnancy on the cardiac cell-extracellular matrix connections in rat offspring, and also to explore prenatal chronic hypoxia-induced possible mechanism of myocardial remodeling.Methods: 25 pregnant SD rats, were divided randomly into 5 groups: Early pregnancy hypoxia group(Pregnancy 1-7 days),Mid-pregnancy hypoxia group(Pregnancy 8-14days),Late pregnancy hypoxia group(Pregnancy 15-21 days),the whole pregnancy hypoxia group(Pregnancy 1-21 days)and Normal oxygen control group,5 rats for each group. 5 male and 5 female offspring rats were randomly selected when they were 1day,1month,3 and 5 month old.Detect blood pressure and heart rate;Weigh the body,kidney, lung, liver, brain weight of offspring rats in each group; Detect diameter of myocardial fibre of offspring rats in each group;The expression of ADAM-9,ADAM-10,ADAM-15,TGF-β1mRNA and the expression of MMP-1,MMP-9,TIMP-1 in local left ventricular of the offspring rats were detected from each groupResults: Prenatal chronic hypoxia induced :①Rat offspring were growth retarded at birth (P<0.01) but of similar weight to controls at 3 months of age. There were significant increases in heart weight of offspring at birth and 3 months of age, and significant decreases in kidney weight of offspring at 3 and 6 months of age (all P<0.05).②High blood pressure in rat offsprings in 3 month ,and higher in 6 month. Higher blood pressure in hypoxia group than normal control group (P<0.05).Male rat offsprings in mid- pregnancy hypoxia group increased most obvious(136.80±2.18&110.20±2.18). No obvious difference heart rate among each grou p(P>0.05).③The expression of ADAM-9,ADAM-10,ADAM-15,TGF-β1mRNA in cardiac muscular tissue was increased in the offspring of hypoxic exposure group (P<0.05),especially in the mid- pregnancy hypoxia group.④Hypertrophic myocardial cells in rat offspring at 6 months, especially in the mid- pregnancy hypoxia group.⑤The expression of MMP-1,MMP-9 in cardiac muscular tissue was increased,the expression of TIMP-1 was reduced in the offspring of hypoxic exposure group (P<0.05), especially in the mid- pregnancy and the whole pregnancy hypoxia group.Conclusion: Prenatal chronic hypoxia can cause offspring rats elevated blood pressure, low birth weight and organ disproportionately grows, it can cause myocardial remodeling by the change of the cardiac cell-extracellular matrix connections and related inflammation factors. Male offspring rats in the mid- pregnancy and the whole pregnancy hypoxia group change most obvious,it hint that obvious change of internal environment in the key time when fetal rats cardiovascular system to develop might cause more critical influence in offspring rats cardiac structure...