| Objective:To investigate the effect of hypoxic pulmonary hypertension (HPH) in pulmonary vascular remodeling of rat and pulmonary in pulmonary tissue;Change of content in endothelin-1 (ET-1 ),nitric monoxide (NO ),thromboxane A2 (TXA2),prostacyclin (PG),Superoxide dismutase(SOD),malondialdehyde(MDA)and expression of cNOS mRNA in the wall of pulmonary artery,further discuss prevention and curing effect of Radix Astragali in HPH induced pulmonary vascular remodeling and modulating function among pulmonary vasoactive substance.Method:21 healthy rats randomly were divided into three groups,each had 7 rats. (1) control group:which was fed in normal environment;(2 ) HPH group:which was fed in hypoxia environment (oxygen concentration was 10.0 +0.5%),8 hours each day,continued 30days;(3) intervention group:which was abdomenly injected every day with Radix Astragali(12g.kg-1) from the first day of lacking oxygen and fed in the same environment as hypoxia group;control group and HPH group was injected with same dosage of normal saline correspondingly. After 30days breeding,rats were injected with 20%Urethane (0.4ml.100g-1) abdomenly for narcosis and mean pulmonary arterial press(mPAP),mean carotid arterial press(mCAP),right ventricle hypertrophy index (RVHI) and content of NO,SOD,MDA,ET-1,TXA2,PGI2 in pulmonary tissue were measured. Change of cNOS content in the wall of pulmonary artery was observed,muscularizing degree of intra-acinar pulmonary artery,relative medial thickness (RMT) and relative medial acreage (RMA) of medium and small pulmonary muscularized arteries and change of pulmonary ultrastructure were measuered.Results: (1) mPAP,RVHI and content of ET-1,TXA2 in the pulmonary tissue of HPH group are markedly increased "more than control group(P<0.01),and intervention group versus HPH group (P<0.05). Content of MDA in pulmonary tissue in HPH group was higher than control group(P<0.01),PGI2 content in pulmonary tissue intervention group is lower than HPH group,but there was no marked difference (P>0.05),marked difference existed between HPH group and control group (P<0.05) (2) content of cNOS,NO and SOD decreased markedly in HPH group than control group (P<0.01),intervention group is higher than HPH group(P<0.05) . (3) muscularizing degree of pulmonary small artery and percentage of RMT RMA in medium and small pulmonary muscularized arteries in HPH group changed markedly than control group (P<0.01),marked difference existed between intervention group and control group(P<0.01) . (4) mCAP among three groups had no marked difference (P>0.05). (5) endotheliocyte of medium and small pulmonary muscularized arteries proliferated,plumped,swelled and smooth muscle cells plumped and there were lots of mitochondrias and endoplasmic reticulums in the cytoplasm.Conclusion:(1) RMT RMA in medium and small pulmonary muscularized arteries of HPH rats increased markedly,rate of loop-muscular artery was increase markedly,rate of non-muscular artery was decreased markedly,non-muscular artery muscularizing was observed,which results in the restructure of pulmonary vessel. (2) NO ET-1 PGI2 TXA2 are related with the pathogenesis of HPVR. (3 )ET-1,PGI2,TXA2 and oxide free radical contents in pulmonary tissue markedly increased in hypoxic group when NO,SOD contents decreased obviously,which results in the restructure of pulmonary vessel. (4) Injection of Radix Astragali decrease the damage on wall cells of pulmonary artery caused by hypoxia and constrain the production of ET-1,TXA2 and oxide free radical and the restructure of pulmonary vessel,and increase contents of NO and SOD. (5) Injection of Radix Astragali performe a preferable preventing and treating effect to HPH. |
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