Effects of endothelial cell injury on pulmonary vascular reactivity.

Using the thiocarbamide model of acute lung injury in rats, we found that alpha-naphthylthiourea (ANTU) caused lung endothelial cell injury, as evidenced by increased permeability edema and decreased angiotensin I conversion. These effects were associated with enhanced pulmonary vascular reactivity. Recurrent ANTU lung injury caused pulmonary hypertension. The water-soluble thiocarbamide thiourea caused cultured vascular endothelial cells to release neutrophil chemoattractant activity. We speculate that endothelial cell injury may modulate the function of vascular smooth muscle and blood leukocytes.