Therapeutic Effect Of Angiotensin-converting Enzyme2on Rat With Experimental Pulmonary Edema After Seawater Drowning

Objective:To study the therapeutic effect of ACE2on pulmonaryedema after sea-water drowning(PE-SWD).Methods：24Wistars rats were divided randomly into3groups:(1)control group with surgical operattion (C group，n=8)；(2) seawaterdrowning group(S group，n=8)；(3) therapeutic group with ACE2(T group，n=8)。Control group with surgical operattion to develop References[1]slightly modified。The routine disinfection、shop towels、anesthesia,fixed rat。For neck midline incision, tracheotomy to insert a "Y" shapedglass casing. Seawater drowning Group: After tracheal intubation，Poured into the sea water rat lungs amount by3ml/kg weight fast[2]，Copy the PE-SWD animal models。ACE2treatment group Preparation:AfterSea suction, immediately given intraperitoneal injection ofrecombinant rat ACE20.1mg/kg[3][4]. After3hours, measured arterialblood gases, Lung wet/dry weight (W/D) ratio, Lung tissue NF-κB,TNF-α and IL-8content, Measurement of NF-κB, TNF-α and IL-8mRNAcontent, Observed the morphological changes of lung pathology withOptical microscope. Using SPSS16statistical analysis software, The twosets of data were compared and Analysised.Results：1. after seawater drowning,Successfully produced acute lung injurymodel.2. Blood gas analysis showed: the seawater drowning group partialoxygen pressure was significantly lower than the control group withsurgical operattion (P <0.05), the partial oxygen pressure of ACE2 treatment group was significantly higher than the sea drowning group(P <0.05).3. Lung pathologic change:The lung damage of Sea water drowning groupwas Observed more serious than control group with surgicaloperattion, lung damage of grade Ⅲ-Ⅳ;The lung damage of ACE2treatment group was Observed less serious than Sea water drowninggroup,lung damage of grade Ⅲ-Ⅳ.4. Lung wet-to-dry weight ratio: wet-dry weight ratio of seawaterdrowning group was significantly higher than the surgical controlgroup, wet-dry weight ratio of ACE2treatment group wassignificantly lower than the seawater drowning group (P <0.05)。5. The pulmonary pathological morphological changes:(1) The lungdamage of Sea water drowning group was Observed more serious thancontrol group with surgical operattion, The lung damage of ACE2treatment group was Observed less serious than Sea water drowninggroup.⑵seawater drowning group pathology semiquantitative scorewas significantly higher than the control group with surgicaloperattion, ACE2treatment group pathology semiquantitative scorewas significantly lower than the seawater drowning group (P <0.05)。6. lung tissue NF-κB, TNF-α and IL-8content: three cytokinesconcentration in seawater drowning group were significantly higherthan the surgical control group (P <0.05), three cytokinesconcentration in ACE2treatment group were significantly lower thanseawater drowning group (P <0.05)。7. Semi-quantitative PCR: Seawater drowning group ACE2semi-quantitative PCR score significantly lower than the surgicalcontrol group (P <0.05), ACE2treatment group ACE2semi-quantitative PCR points significantly higher than the seawater drowning group (P<0.05)。 Conclusion：The model with seawater drowning was successfully modeled throughpouring the seawater into rat lung. After Seawater drowned,ratsshortness of breath, oxygen partial pressure decreased, lung damaged,lung wet-dry weight ratio increased, the contents of lung NF-κB, TNF-αand IL-8decreased. After ACE2injected by intraperitoneal, Lung damagereduced, ACE2content of lung tissue Increased. These indicated thatthere is protective effect with ACE2.