FORMIC-ACID IS A PRODUCT OF THE ALPHA-OXIDATION OF FATTY-ACIDS BY HUMAN SKIN FIBROBLASTS - DEFICIENCY OF FORMIC-ACID PRODUCTION IN PEROXISOME-DEFICIENT FIBROBLASTS

Human skin fibroblasts in culture can oxidize beta-methyl fatty acids, such as phytanic acid and 3-methylhexadecanoic acid, to CO2 and water-soluble products. The latter are released largely into the culture medium. The major water-soluble product formed from [1-C-14]phytanic and [1-C-14]3-methylhexadecanoic acids is [C-14]formic acid. As phytanic acid and 3-methyl-hexadecanoic acids contain beta-methyl groups and theoretically cannot be degraded by beta-oxidation, we postulate that formic acid is formed from fatty acids by alpha-oxidation. The marked reduction in formic acid production from beta-methyl fatty acids in peroxisome-deficient skin fibroblasts suggests that peroxisomes are involved in the generation of C1 units.