Enhanced expression of cytosolic fatty acid binding protein and fatty acid uptake during liver regeneration in rats

Background/Aims: Cytoplasmic liver fatty acid binding protein (L-FABP) has been suggested to be associated with cellular mitotic activity but the changes in L-FABP mRNA and protein levels during liver regeneration following partial hepatectomy (PHx) are not clear. Methods: In the present study, we determined the time course of L-FABP mRNA expression and L-FABP levels following 70% PHx using Northern and Western blot, respectively. To elucidate one of the roles for L-FABP in PHx, [3H]-palmitic acid clearance in hepatocytes isolated from 24 h post-PHx and control animals was assessed. Results: L-FABP mRNA increased at 30 min, peaked at approximately 1 h (163 ± 17%; mean ± SE, n= 5), and returned to control levels 6 h post-PHx. L-FABP level also increased at 1 h but peaked at 24-h (219 ± 41%; mean ± SE, n= 5). Hepatocyte [3H]-palmitic acid clearance increased by 29% at 24-h post-PHx, suggesting an increased intracellular transport (or binding) function by L-FABP. Pre-treatment with dexamethasone statistically reduced L-FABP levels (29%) and suppressed the regenerative process (mitotic activity). Conclusions: L-FABP mRNA increased sharply in response to PHx but the increase was short lived, while L-FABP level increased at a later stage. Both L-FABP content and fatty acid uptake increased significantly during liver regeneration induced by PHx in rats. It is likely that L-FABP is one of the factors responsible for hepatic regeneration. (Mol Cell Biochem 262: 41–49, 2004)