Mechanisms of sebum production and delivery in man.

Utilizing a solvent extraction system and colorimetric analysis, surface lipid levels were determined on the forehead. To understand the mechanisms involved in the sebaceous gland apparatus, repeated sampling at varying timed intervals were made. The data suggest that frequent surface samplings produce higher rates of lipid replacement. The increasing lipid replacement rates seen with sampling intervals of greater frequency do not follow a linear pattern. Also, lipid replacement rates show a gradual decline with time. This data suggest the existence of a multifunctional sebaceous apparatus involved in sebum production (a rate function), sebum storage (a volume function) and surface delivery (a rate function).