The expression of lipoprotein lipase activity and mRNA in mesenchymal rat heart cell cultures is modulated by bFGF

Abstract

The effect of basic fibroblast growth factor (FGF) on lipoprotein lipase (LPL) production was studied in mesenchymal rat heart cell cultures. Addition of FGF to culture medium containing 20% serum resulted in a 3-fold increase in LPL activity. The minimal effective dose of FGF was 10 ng/ml and the increase occurred after exposure for 48 h. Addition of FGF was effective during the first week in culture, when enzyme activity was increasing, but not after 11 days when the cultures were superconfluent and the enzyme activity was high. Addition of FGF to serum-poor medium was able to replace serum required to sustain LPL activity. In FGF-treated cultures, more LPL activity was present in the functional pool, but not in the medium, than in the controls. The increase in enzymic activity was accompanied by an increase in enzyme mass and in LPL mRNA.