Effects of continuous adenosine infusion on pulmonary hypertension in chronically hypoxic rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effects of continuous subcutaneous adenosine infusion on pulmonary hypertension in chronically hypoxic rats.</p><p><b>METHODS</b>Twenty-four SD rats were randomized into normoxic group, hypoxic group and adenosine-treated hypoxic group. Hypoxic environment was simulated in a chamber filled with 10% oxygen and 90% nitrogen. After 7 days of hypoxia, adenosine were administered subcutaneously in the rats in adenosine-treated group at the rate of 100 microg kg(-1) min(-1) via an Alzet micro-osmotic pump for 14 days, while the pumps in the other two groups contained normal saline. After 21 days of hypoxia, pulmonary artery pressure and tail-cuff blood pressure were measured, with the plasma rennin activity (RA), angiotensin II (AngII), endothelin (ET)-1, and nitric oxide (NO) determined. Inducible nitric oxide synthase (iNOS) expression in the pulmonary artery of the rats was detected using immunohistochemical method.</p><p><b>RESULTS</b>The mean pulmonary artery pressure (mPAP) was significantly higher in the hypoxic group than that in the normoxic group (P<0.01) and in the adenosine-treated group (P<0.01). Plasma ET-1 was significantly higher but plasma NO significantly lower in the hypoxic group than in the normoxic group (P<0.01) and the adenosine-treated group (P<0.01). iNOS expression in the pulmonary artery was higher in the hypoxic group than in normoxic group (P<0.01), and adenosine significantly increased iNOS expression in comparison with the normoxic and hypoxic groups (P<0.01). Plasma RA and AngII in the hypoxic group were significantly higher than those in the normoxic group (P<0.01) and the adenosine-treated (P<0.01).</p><p><b>CONCLUSION</b>Adenosine administered by continuous subcutaneous infusion alleviates chronically hypoxia-induced pulmonary hypertension in rats, in which rennin angiotensin system, ET-1, and iNOS/NO play a role.</p>

Continuous Administration of Adenosine by Peripheral Pathway Attenuate Myocardial Hypertrophy and Pulmonary Arterial Hypertension Induced by Hypoxia in Rats / 实用儿科临床杂志

Objective To explore if continuous administration of adenosine by peripheral pathway can attenuate myocardial hypertrophy and pulmonary arterial hypertension(PAH)caused by chronic hypoxia and analyze the dose-effect relationships between them.Methods Forty-eight Sprague-Dawley(SD)rats were randomly divided into 8 groups:the hypoxia group(n=6),the hypoxia ade-nosine-treated groups [n=18,adenosine was administrated with different doses 50,100,150 ?g/(kg?min),the hypoxia adenosine-treated group A,B,C],the control group(n=6),the control adenosine-treated control groups [n=18,adenosine was administrated with different doses 50,100,150 ?g/(kg?min),the control adenosine-treated control group A,B,C].On the 21st day of the experiment,the Medlab-U/4CS was used to determined the right ventricular systolic pressure(RVSP)and the mean pulmonary arterial pressure(mPAP)of each rat.The ratio of the weight of right ventricle/left ventricle and septum[RV/(LV+S)] and the ratio of the weight of right ventricle/body weight(RV/BW)were also calculated.The morphological changes in myocardium cells and pulmonary vascular structure were observed.SAS 8.0 software was used to analyze the data.Results Twenty-one days after hypoxia,RVSP,mPAP,RV/(LV+S),RV/BW in hypoxia groups were higher significantly than those in control group and hypoxia adenosine-treated groups(Pa