Abatement of bleomycin-induced increases in vascular permeability, inflammatory cell infiltration, and fibrotic lesions in hamster lungs by combined treatment with taurine and niacin.

BACKGROUND

The bleomycin (BL) hamster model of interstitial pulmonary fibrosis has been widely used to study the pathogenesis of interstitial pulmonary fibrosis and to screen potentially desirable antifibrotic agents. We have recently shown that taurine and niacin in combination, diminished BL-induced increases in lung lipid peroxidation and hydroxyproline content in hamsters. In the present study, we have evaluated the effects of taurine and niacin on the bronchoalveolar lavage (BAL) cells, and morphologic and morphometric features of the lung in the same model of pulmonary fibrosis.

EXPERIMENTAL DESIGN

The hamsters were divided into 4 groups: saline; taurine + niacin + saline; BL; and taurine + niacin + BL. Treatment of taurine and niacin began 2 days before the first intratracheal instillation of saline or BL and thereafter daily throughout the study for taurine + niacin + saline and taurine + niacin + BL groups. Hamsters received BL or saline in three consecutive doses at weekly intervals by intratracheal route. Twenty days after the last intratracheal instillation, the hamsters were sacrificed for various studies.

RESULTS

Combined treatment with taurine and niacin suppressed BL-induced inflammation and almost completely abrogated pulmonary fibrosis in hamsters. Two independent studies showed that taurine and niacin in combination significantly reduced BL-induced increases in bronchoalveolar inflammatory cell counts, protein content, and acid phosphatase activity. By both light and electron microscopy, the lungs of hamsters treated with BL and taurine and niacin had much fewer inflammatory cells, less epithelial necrosis and collagen deposition than hamsters treated with BL alone.

CONCLUSIONS

The results of this investigation suggest that combined treatment with taurine and niacin is effective against the development of lung fibrosis in the BL-hamster model and offers a novel therapeutic modality in the prevention of the fibrotic processes.