OBJECTIVETo investigate the mechanism of pulmonary circulation obstacle in chemicals-induced acute lung injury and its clinical significance.

METHODPulmonary arterial intubation, circulating endothelial cells (CEC) isolation and hemorheology detection technique were used to observe the changes of CEC numbers and hemorheology in rat pulmonary vascular system during oleic acid-induced acute lung injury (ALI).

RESULTSThe numbers of CEC were obviously increased even in the early phase of ALI [from (2.06 +/- 0.48)/0.9 micro l to (5.50 +/- 0.54)/0.9 micro l]; there was no obvious change in whole blood viscosity under high shear rate (200 s(-1), 30 s(-1)) but the whole blood viscosity and hematocrit were remarkably increased in pulmonary artery blood at low shear rate (5 s(-1), 1 s(-1)) (P < 0.05). Erythrocytes had increasing tendency, whereas platelets were also decreased but there was no statistical significance.

CONCLUSIONThe deterioration of pulmonary circulation may be the key point in the pathogenesis of ALI; the injury and dysfunction of pulmonary capillary endothelial cells (PCEC) may be the common starting phase in the pathological processes of ALI; the detection of CEC may offer a new valuable and sensitive index for diagnosis of ALI.