Abstract:

Abstract:Objective To establish rat models with pulmonary artery hypertension induced by monocrotaline(MCT) and to observe the pathological changes of lung tissue.Methods Seventy male Wistar rats were randomly devided into three group:control group(n=10),50 mg·kg^-1 MCT group(n=30),60 mg·kg^-1 MCT group (n=30).At two weeks and four weeks after injected intraperitoneally with MCT(injected intraperitoneally with equal normal saline in control group),the right ventricular systolic pressure(RVSP)and right ventricle weight/left ventricle+septum weight ［RV/(LV+S)］ ratio were measured.Hematoxylin -eosin staining and orcein technique were used to observe the pathological changes of lung tissue and pulmonary arterioles’medial thickness.Results Two weeks or four weeks after MCT administration,RVSP in 50 mg·kg^-1 MCT group was higher than that in control group（respectively 36.6 mmHg±5.1 mmHg，39.1 mmHg±7.0 mmHg versus 26.1 mmHg±3.8 mmHg，both P<0.01）,and  RV/(LV+VS) weight ratio increased greatly（respectively 0.289 4±0.021 7，0.409 4±0.125 6 versus 0.247 3±0.019 3,both P<0.01）,so were the results in 60 mg·kg^-1 MCT group compared with control group:RVSP respectively 33.8 mmHg±5.5 mmHg,46.6 mmHg±12.6 mmHg versus 26.1 mmHg±3.8 mmHg，both P<0.01;RV/(LV+VS) weight ratio,respectively 0.308 2±0.058 4,0.417 5±0.103 7 versus 0.247 3±0.019 3,both P<0.01.There was no significant difference of RVSP and RV/(LV+VS) weight ratio between two different doses of MCT groups. The pulmonary arterioles were markedly thickened in both 50 and 60 mg·kg-1 MCT groups compared with control group（21.3%±1.9%,23.4%±2.3% versus 11.3%±1.2%,respectively P<0.01).The rats in 60 mg·kg^-1 MCT group were half dead by the day 47 and none survived by the day 63,yet none of rats in 50 mg·kg^-1 MCT group was dead by the day 47 and seventy percent survived by the day 63.Conclusion Both 50 and 60 mg·kg^-1 MCT  can induce pulmonary artery hypertension and there were no pathological differences between them，but the survival of rats treated by the former dose is longer than that by the latter one.

Key words: monocrotaline;models,animal;hypertension,pulmonary