[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 (CdCl(2)), 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 CdCl(2) 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 reverted by LGF.

Conclusions: Together, these data seem to demonstrate that LGF is able to improve lung function and partially reverts the increase in lung matrix proteins produced by CdCl(2) instillation.