Changes of distribution of platelet activating factor in the lung of rats with hypoxic pulmonary hypertension.

OBJECTIVE To investigate the role of platelet activating factor (PAF) in the hypoxic pulmonary hypertension.

METHODS Fifteen of 30 male Wistar rats were exposed to hypoxia for 3 weeks, and another 15 rats served as controls. The pulmonary arterial pressure was examined by catheterization. The sections of rat lung were treated by the avidin-biotin-peroxidase complex method to expose the location of PAF.

RESULTS The rats developed pulmonary hypertension and right ventricular hypertrophy after hypoxic exposure. Under the light microscope, PAF is distributed on the vascular and alveolar walls of normal lung, and the content of PAF in the lung of rats with hypoxic pulmonary hypertension are remarkably higher than those of normoxic controls.

CONCLUSIONS PAF plays not only a physiological role in the rat lung, but also a pathophysiologic role in hypoxic pulmonary hypertension.