The effect of unilateral pneumonectomy on in vitro drug metabolism by the contralateral lung of rabbits.

The effect of unilateral pneumonectomy on the drug-metabolizing capability of the remaining lung of male rabbits was studied 3, 10, and 28 days after surgery. During the period of compensatory lung growth which follows pneumonectomy, the contralateral lung had a reduced ability to metabolize some model drug substrates. The activities of 4-chloro-N-methylaniline demethylase, glutathione transferase, and 4-aminobenzoate N-acetyltransferase were significantly decreased in pneumonectomizd animals relative to shamoperated controls at 10 days. By 28 days most of these parameters of drug metabolism had returned to control levels. Lung hydroxyproline concentration, an index of collagen, did not differ in pneumonectomized and control animals at any of the time points. 3-Methylcholanthrene failed to induce the pulmonary mono-oxygenase system in pneumonectomized animals. The response of pulmonary drug-metabolizing enzymes to unilateral pneumonectomy in rabbits was temporally and qualitatively similar to the response in rat liver following partial hepatectomy.