Objective: Effect of two antifibrotic Chinese drugs, 764-3 and ligustrazine, on collagen content in chronic hypoxic pulmonary hypertensive extrapulmonary arterial wall were examined.
Methods: Since collagen contains more than 10% hydroxyproline by weight and in other proteins there are almost no hydroxyproline, collagen content was expressed as micrograms of hydroxyproline. Hydroxyproline was determined by calorimetric method after oxidized by chloramine T.
Results: Both 764-3 and ligustrazine significantly inhibited the increase of pulmonary arterial pressure and elevation of hydroxyproline content in extrapulmonary arterial wall during chronic hypoxia.
Conclusions: 764-3 and ligustrazine may be two hopeful therapeutic drugs for chronic hypoxic pulmonary hypertension.