Metabolic studies on isolated hair follicles: hair follicles engage in aerobic glycolysis and do not demonstrate the glucose fatty acid cycle.

The matrix cells of the hair follicle have one of the highest rates of cell division in the mammalian body, but their fuel metabolism is poorly understood, due mainly to the difficulty in obtaining viable intact follicles from the skin. We have previously shown that viable and intact rat hair follicles can be isolated by shearing, and in this study we now report on their fuel metabolism. In this study we have shown that the hair follicle exhibits aerobic glycolysis, in that of the total glucose utilized by the hair follicle, only 10% is oxidized to CO2. We have also shown that, in the absence of glucose, the hair follicle is capable of utilizing other fuels such as palmitate and beta-hydroxybutyrate. However, neither palmitate or beta-hydroxybutyrate had any effect on the rate of glucose utilization or on [U-14C] glucose oxidation, showing that glucose sparing via the glucose fatty acid cycle does not operate in the hair follicle. Measurements of glucose flux through the pentose phosphate pathway accounted for only 3% of the total glucose utilized by the hair follicle, although this value represented 32% of the total glucose oxidized. Both palmitate and beta-hydroxybutyrate inhibited glucose flux through the pentose phosphate pathway.