[Liver growth factor improves pulmonary fibrosis secondary to cadmium administration in rats]

Introduction Liver growth factor (LGF) is a liver mitogen with regenerating and anti-fibrotic activity even at extrahepatic sites. We used LGF in a lung fibrosis model induced by cadmium chloride (CdCl2), to study its antifibrotic capacity. Methods Forty-two male Wistar rats were administered a single dose of 0.5ml/rat of CdCl2 0.025% (n = 21) or the same volume of saline (control group, n = 21). After 35 days, once a lesion was established, we started a 3 week treatment with LGF, after which we determined lung function ––inspiratory capacity (IC), lung compliance (LC), forced vital capacity (FVC) and expiratory flow at 75% (FEF75%)––, lung morphometry ––alveolar internal area (AIA), mean linear intersection (LM)––, and collagen (both by Sirius red and hydroxyproline residues) and elastin contents. Results Pulmonary fibrosis in CdCl2 rats was characterized by a marked decrease in pulmonary function with respect to healthy controls ––reductions of 28% in IC, 38% in CL, 31% in FVC, and 54% in FEF75%–– which was partially recovered after LGF injection ––18% IC, 27% CL, 19% FVC and 35% FEF75%––; increase in collagen and elastin contents ––165% and 76%, respectively, in CdCl2 rats, versus 110% and 34% after LGF injection––; and increases in AIA and LM, partially inverted by LGF. Conclusions Together, these data seem to demonstrate that LGF is able to improve lung function and partially inverts the increase in lung matrix proteins produced by CdCl2 instillation.