SKF 104976 is a 3,2-carboxylic acid derivative with potent 14-alpha-demethylase (14 alpha DM) inhibitory activity. SKF 104976 inhibited 14 alpha DM activity by 50% at 2 nM in Hep G2 cell extracts. SKF 104976 inhibited the incorporation of [14C]acetate into cholesterol in intact cells at similar concentrations, accompanied by accumulation of lanosterol, and resulted in a 40-70% decrease in 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) activity. SKF 104976 did not affect the uptake and degradation of low-density lipoprotein in Hep G2 cells, indicating that HMGR and low-density lipoprotein receptor activities are not coordinately regulated under these conditions. The inhibitory effect of SKF 104976 on HMGR activity remained unchanged even when the flux of carbon units in the sterol synthesis pathway was reduced by 80%. SKF 104976 did not inhibit HMGR activity under conditions where sterol synthesis was almost completely blocked by lovastatin[1].
