The Studies Of Hispathology And Hemodynamic On Chickens Inoculated With Highly Pathogenic Avain Influenza

Clinical symptoms, pathological anatomy, histopathology and hemodynamics were monitored on 45 days laying-egg chickens inoculated with avain influenza virus (AIV) A/chicken/hebei/2002(H5N1) at different intervals(20h, 40h, 60h and 72h) after inoculation.The feromal artery pressure (FAP), pulmonary artety pressure (PAP) and right ventricular pressure (RVP) were measured at the same intervals.The results were as follows:1. Laying-egg chickens inoculated with virus showed 100% morbidity and 94% mortality,from which can conclude the aivain influenza virus was highly pathogenic to chickens. Clinical symptoms began at hour 18 postinoculation(PI 18),and the death began at PI20 ,then the mortality reached its peak from inoculated 60h to 72h.In histopathologic investigation,the histologic changes caused by virus were hyperemia,hemorrhage,degeneration and necrosis in the myocardium,iung,kidney,liver,pancreas,spleen and thymus.Especially in the fat of coronary groove.the multifocal haemorrhages is serious.2. Mean femoral artery pressure(mFAP),femoral artery systolic pressure(FASP) and femoral artery diastolic pressure(FADP) were decreased significently at PI20.The findings indicated significent phathologic changes in systemic circulation and the cardiac output of the infected chickens decreased.The results suggested the heart function decrease because of AIV attacking cardiac myocytes,on the other hand , the vascular endothelial cell was infected and enduced to the phathology which led to dysfunction of circulation.3.Pulmonary artery systolic pressure(PASP) and pulmonary artery diastolic pressure(PADP) were increased progressively during the infection. RASP increased significantly from (2.31±0.35 kpa) to (3.03±0.51 kpa) at PI72 while the PADP was not significantly different compared with the normal.The systemic and pulmonary circulation were affected, the ascending in RASP and PADP were concerned with the histopathology in pulm.4. Right ventricular systolic pressure(RVSP) increased significantly at PI60 and right ventricular diastolic pressure(RVDP) showed the same result at PI20. These data suggest the right ventricular dysfunction caused by increasing in PAP, on the other hand, the virus led to right venticular dysfunction because of ischemic and anoxia.