In vitro primary mouse hepatocyte SCF production in response to IL-6. Primary mouse hepatocytes were stimulated with 20 ng/ml IL-6 or media alone. Supernatants and supernatants plus cells were harvested at various timepoints and SCF levels were measured by ELISA. Supernatant SCF levels were used to determine levels of soluble SCF. For quantitation of soluble + bound SCF, supernatants plus cells were sonicated and SCF levels in this solution were measured as an estimate of soluble + bound SCF. There were no significant differences noted in levels of soluble compared with soluble + bound SCF in cells incubated in media alone. There were significant increases in soluble SCF levels at all timepoints from cells treated with IL-6 (^#P < 0.05 vs. media alone). In addition, levels of soluble + bound SCF were significantly increased after IL-6 treatment compared with treatment with media alone (*P < 0.01 vs. media alone). Furthermore, levels of soluble plus bound SCF were significantly increased compared with levels of soluble SCF alone after IL-6 treatment at all timepoints (^†P < 0.05 vs. soluble levels). Data are expressed as the mean ± SEM. Thin line, cells incubated with media alone and assayed for soluble SCF; heavy line, cells incubated with media alone and assayed for soluble and bound SCF; open circles, cells stimulated with IL-6 (20 ng/ml) and assayed for soluble SCF; closed circles, cells stimulated with IL-6 (20 ng/ml) and assayed for soluble plus bound SCF.