| Abstract: | Sebostasis in the aged male is a frequent and commonly accepted fact. In order to evaluate the sebostasis of the aged, several experimental parameters were developed to obtain valuable data with regard to the activity of sebaceous glands. The average areas of the lobes of the sebaceous glands and sebocytes, as well as those of the nuclei of sebocytes, were evaluated planimetrically. By means of chromatographic analysis, the skin surface lipids were determined. Using silicone stamping, the average extention of the pore openings was quantitatively measured. Although elderly men show significantly larger sebaceous glands than young people, the concentration of the skin surface lipid is clearly reduced. The transit time is diminished and the drastically reduced intrasebocytic sebum synthesis is of pathogenetic nature. Whereas, namely in young men, the volume of the differentiating sebocytes increases continuously, it remains small in elderly men. As a characteristic expression of this reduced differentiation, the sebocyte nucleus shrinks only very little while the cells migrate from the periphery to the center of the lobe. Consequently, the sebocytes set free only small amounts of sebum with considerable retardation. The qualitative composition of the skin surface lipids in the aged shows differences in respect to the cholesterol and squalene concentrations. The areas of pore openings on the skin surface shrink, probably as a consequence of a reduction of cutaneous elasticity.The present findings show clearly that sebostasis in the aged is caused by an altered differentiation of the sebocytes themselves. It is unknown whether or not normal influences undergo a decline or whether a deficiency of sebumrelated enzymes plays a role. |
