High altitude hypoxia environment changes of the content of RAAS and right ventricular ACE2 activity in adult SD rats

Abstract

Objective To study the function of the rennin-angiotensin-aldoterone system(RAAS) under high altitude hypoxia environment and objective to investigate the effects of high altitude hypoxia on the angiotensin conversion enzyme 2(ACE2) mRNA and protein expressions in SD rat right ventricle. Methods Forty male adult Sprague Dawley( SD) rats, under high altitude hypoxia environment were divided randomly into 4 groups: the control group(D group, Xi'an area 5m above sea leve1), the 1-day (A group)hypoxia group, the 3-day(B group) hypoxia group and the 30-day (C group)hypoxia group. To move the standardized healthy male SD rats to high altitude environment 1d brings up Qinghai Gelmu ( height above sea level 2700m ) and 3d to bring up Tibet Naqu( height above sea level 4500m ) and 30d Tibet Naqu when 3 experimentals group animals from plain(5m above sea leve1). and use radiating immunity law ( RAI ) is ascertained by measuring great rat plasma the concentration of PRA, AT II, ALD in 4 groups. ACE2 mRNA and p rotein of right ventricle were measured by RT-PCR and Western blot. Results A's series plasma PRA's content act as 5.15 ±s 0.86, AT II's content act as 92.10±10.25, ALD's content act as 85.60 ±s 29.40; B's series plasma PRA's content is 7.12 ±s 0.31, AT II's content act as 160.53±10.84, ALD's content act as 56.30±25.23;C's series plasma PRA's content is 5.37 ±s 0.28, AT II's content act as 127.45±30.6, ALD's content act as 82.54±26.78.ACE2 mRNA and ACE2 protein synthesis in right ventricle were increased accordingly after 30-day exposure to high altitude hypoxia (P < 0.01). Conclusion RAAS is concerned with acclimatization hige altitude hypoxia environment and have important effect. ACE2 mRNA of the right ventricule and ACE2 protein synthesis were increased under high altitude hypoxia environment, suggesting that ACE2 may play a role in high altitude hypoxic adap tation of the heart.