Objective: To investigate the role of angiotensin converting enzyme inhibitor (ACEI) in the treatment of acute respiratory distress syndrome (ARDS).
Methods: Changes in physiological and biochemical indexes, and circulating endothelial cells (CEC) were observed in rats of oleic acid-induced ARDS with ACEI-Captopril (Cap) therapy and controls, respectively.
Results: Under the normal systemic blood pressure, Captopril therapy showed good effect on ARDS in rats. Two hours after administration of Captopril, their pulmonary arterial pressure reduced to (14.43 +/- 1.51) mm Hg (1 mm Hg = 0.133 kPa), approximating to normal level, from (23.50 +/- 5.79) mm Hg. The number of CEC, which reflected injuries in pulmonary capillaries, decreased to (4.25 +/- 0.20)/0.9 micro l from (6.88 +/- 1.90)/0.9 micro l. Value of oxygen pressure in arterial blood (PaO(2)) increased to (70.48 +/- 9.54) mm Hg from (35.08 +/- 4.59) mm Hg. In the mean time, ratio of wet to dry lung weight was returned to nearly normal. So, it indicated that high-dose of oleic acid could only induce mild lung injury, and the development of ARDS was obviously inhibited by ACEI.
Conclusions: ACEI may effectively depress pulmonary arterial hypertension, block the development of ARDS, and have certain good protective effect on pulmonary capillary endothelia.