Study Of Hemin In Intermittent Hypoxic Rat

Objective To study the influence of hemin on the blood pressure of intermittent hypoxic rats and evaluate its possibility to treat hypertension caused by intermittent hypoxia.Methods 24 Sprague-Dawley(SD)male rats were randomly divided into experiment group(group A),control group(group B)and blank group(group C).30 minutes after injected with hemin,group A was exposed to intermittent normobaric hypoxic environment(8 h/day).Group B was injected with normal sodium and then exposed to the same environment(8 h/day).Group C just inhaled air in the room.The three groups were bred in the same condition.35 days later,the carotid artery pressure(CAP)of rats was measured and their plasma carbon monoxide(CO)was done by Chalmer's method.Transcriptase polymerase chain reaction(RT-PCR)was performed to detect the levels of HO-1 mRNA expression in lung,liver,spleen,kidney and other's rats' organs.The expression of HO-1 protein in the organs was also detected by immunohistochemistry.Results①The mean carotid artery pressure:The mean carotid artery pressure in group B was significantly higher than group A and group C(P＜0.05).The mean carotid artery pressure in group A was higher than group C but lower than group B (P＜0.05).②The concentration of plasma CO:Plasma CO in group A was higher than group B and group C(P＜0.05).there was no statistics difference of plasma CO between group B and C(P＞0.05).③The of lung,liver,spleen and kidney in group A and B was higher than group C(P＜0.05).The expression of HO-1 mRNA in group A was also higher than group B(P＜0.05).④There were no relationship between the mean carotid artery pressure and the concentration of plasma CO of kidney in hypoxic group rats(r=0.399,P=0.327).There were significant negative relationship between the mean carotid artery pressure and the concentration of plasma CO and HO-1 mRNA expression of kidney in hemin group rats(r=-0.909, P=0.002).Conclusions Intermittent hypoxia could lead to hypertensive rats.The HO-1 expression was increased in hypoxic rats,but the plasma CO did not have significant increase.The inducer of HO-1(hemin)could increase the expression of HO-1 and CO of the hypoxic rats,then lower their blood pressure caused by intermittent hypoxia to some extent.