[The role of platelet activating factor in chronic pulmonary hypertension]

To investigate the chronic effects of platelet activating factor (PAF) on pulmonary circulation, we administered PAF to 15 male Wistar rats in low doses by intraperitoneal injection for 28 days. The results showed that after PAF treatment the mean pulmonary arterial pressure increased by 1.17 kPa, the pulmonary vascular resistance increased by 2409.3 kPa.s/L, the cardiac output decreased by 9.1 ml/min and the ratio of right ventricular weight to left ventricular plus septal weights increased by 0.1, compared with control. Histologic sections of the lungs were examined under light microscope equipped with a computerized image analyser. The wall of pulmonary arterioles was thickened; the percent of vascular wall thickness/vascular external diameter and percent of vascular wall area/total vascular area were increased in the PAF group (P < 0.05). These suggest that PAF may play an important role in the pathogenesis of chronic pulmonary hypertension.