Selective reduction of phosphatidylglycerol and phosphatidylcholine in pulmonary surfactant by 4-aminopyrazolo(3,4d)pyrimidine in the rat

Abstract

Effects of 4-aminopyrazolo(3,4d)pyrimidine on pulmonary surface-active material and its surface activity were investigated in the rat. A rapid decrease in serum cholesterol was observed in rats treated with this drug and these effects continued during the entire period of treatment. Phosphatidylglycerol content in surface-active material and in the residual lung decreased significantly during three days of treatment and phosphtidylcholine content in surface-active material also decreased on the third day of the treatment. There were no changes in the contents of other phospholipids and cholesterol. The surface-active material from treated rats showed a larger surface compressibility, an elevated minimum surface tension, and a low stability index, as compared to control rats. These results show that alteration of lipid constituents significantly affects the surface properties of pulmonary surface-active material and that 4-aminopyrazolopyrimidine is a drug which can be effectively utilized to investigate lipid metabolism of the lung.