The effects of vardenafil on high altitude pulmonary hypertension in rats / 天津医药

ABSTRACT

Objective To investigate the effect of vardenafil on high altitude pulmonary hypertension in rats, and the possible mechanism thereof. Methods Thirty rats were randomly divided into three groupscontrol group with normal-pres?sure and normal-oxygen (group C), pulmonary hypertension group with low-pressure and low-oxygen (group P), and the group treated by vardenafil in low-pressure and low-oxygen condition (group V). The rats of group P and group V were ex?posed to low-pressure and low-oxygen condition in an auto-modulating hypobaric and hypoxic cabin to simulate 5 000 m high altitude environment (air pressure 50 kPa, oxygen concentration 10%) for 8 hours daily. Vardenafil (1 mg/kg) was given by gastrogavage to rats in group V once daily for 4 weeks, while the isodose distilled water was given by gastrogavage to rats in group C and group P. The mean pulmonary arterial pressure and right ventricular mass index were measured respectively after 4-week treatment. Morphologic changes of peripheral pulmonary artery were detected by light microscope. The serum levels of nitric oxide (NO) and endothelin-1 (ET-1) were detected as well. Results The pulmonary arterial pressure and right ventricular mass index were significantly higher in group P than those of group C and group V (P<0.05). The ratio of vascular medial wall thickness to external diameter (WT%) and the ratio of pulmonary artery wall area to tube area (WA%) were significantly increased in group P than those of group C and group V (P<0.05). Furthermore, the serum level of NO was significantly lower in group P than that of group C and group V, but the serum level of ET-1 was significantly increased compared with that of group C and group V (P<0.05). Conclusion Vardenafil can effectively reduce the pulmonary arteri?al pressure, and attenuate pulmonary vessels and right ventricle remodeling induced by high altitude pulmonary hypertension.