Objective To explore the therapeutic effect of angiotensin-converting enzyme 2( ACE2) on pulmonary edema after sea-water drowning.
Methods Twenty-four Wistar rats were randomly divided into 3 groups, ie. a control group, a seawater drowning group, and an ACE2 treatment group. The rats in the seawater drowning group and the ACE2 treatment group were infused sea-water into their lungs. Then the rats in the ACE2 treatment group were intraperitoneally injected with recombinant rat ACE2. All rats were killed at the time point of 3 hours. Rat arterial blood gas was analyzed and wet /dry weight ratio of lung tissue was measured. The IL-8 content in lung tissue was measured with enzyme linked immunosorbent assay. Pathological changes of lung tissue were observed under light microscope.
Results Acute lung injury induced by seawater drowning was successfully reproduced in the rats. The PaO2 in the seawater drowning group was significantly lower than that in the control group and the ACE2 treatment group [ ( 52. 34 ±2. 69) mmHg vs. ( 96. 40 ±3. 47) mm Hg and ( 64. 58 ±3. 42) mm Hg, P  lt;0. 05] . The lung W/D ratio and IL-8 level in the seawater drowning group were significantly higher than those in the control group and the ACE2 treatment group ( 8. 30 ±0. 24 vs. 4. 49 ±0. 19 and 5. 65 ±0. 25, P  lt; 0. 05; 1112. 2 ±40. 02 vs. 440. 39 ± 4. 06 and 858. 56 ±9. 92, P  lt;0. 05) . Lung pathological examination revealed hemorrhage and hyaline membrane formation, alveolar and interstitial edema in the seawater drowning group while those changes significantly relieved in the ACE2 treatment group.
Conclusion ACE2 treatment has therapeutic effects on acute lung injury induced by seawater drowning.

Citation： LI Tianlin,WEN Wen,LAI Guoxiang,LIU Deling,ZHANG Lei.. Therapeutic Effect of Angiotensin-Converting Enzyme 2 on Rats with Experimental Pulmonary Edema after Seawater Drowning. Chinese Journal of Respiratory and Critical Care Medicine, 2012, 11(6): 537-540. doi: Copy