PROTEIN-KINASE-C AND LINOLEIC ACID-INDUCED INHIBITION OF MELANOGENESIS

Linoleic acid has been shown to inhibit melanogenesis in cultured B16 mouse melanoma cells. We report here the possible involvement of protein kinase C (PKC) in linoleic acid-induced inhibition of melanogenesis in B16 cells. A single PKC subspecies (alpha-PKC) was detected in B16 cells. The enzyme was activated by linoleic acid in vitro. The effective concentrations at which PKC was activated (25-mu-M; maximum response) were consistent with those for the inhibition of melanogenesis in cell culture system. In addition, the permeable diacylglycerol 1-oleoyl-2-acetyl glycerol that activates PKC also inhibits melanogenesis at 100-mu-M. These results suggest that activation of PKC plays a pivotal role in the linoleic acid-induced inhibition of melanogenesis in B16 cells.