Ambroxol increases the choline but not fatty acid incorporation into lung phospholipids in experimental lung disorders.

Ambroxol, a drug capable of elevating the phospholipid content in healthy rabbit lungs, was tested on two models of experimental lung injury, lung changes in sepsis induced by a peritonitis and in bromcarbamide intoxication. The phospholipid content of the lungs and the synthesis of the individual phospholipids phosphatidylcholine (PC) and sphingomyeline were measured in vitro by incubation of lung slices with labeled phospholipid precursors. Influenced by the drug, the phospholipid content increases to 132% in the peritonitis experiments and to 111% in the bromcarbamide experiments. The peritonitis experiments show the increase in phospholipid synthesis to result from an enhanced choline incorporation into PC up to 192% and into sphingomyeline up to 630%. The values for the bromcarbamide experiments are 411% for PC and 485% for sphingomyeline, respectively. There was no statistically significant difference in the incorporation of fatty acids in the treated and untreated animals. We conclude that ambroxol possibly stimulates the phospholipid synthesis in injured lungs by stimulating the choline phosphatcytidyltransferase, but not the incorporation of fatty acids into PC in those lungs. These findings may be important to the surfactant system of the lung consisting mainly of PC.