The hamster ear sebaceous glands. I. Examination of the regional variation by stripped skin planimetry.

A stripped skin planimetric method was developed to measure the ear sebaceous gland areas using a Numonics Graphics Calculator. The ear skin was manually separated from the cartilage and the area of the sebaceous gland units observed from the underside was determined. This procedure is less time-consuming than standard histologic techniques. Using stripped skin planimetry, it was demonstrated that the sebaceous gland size was greatest at the basal region of the ear and decreased toward the periphery. Regional variations in the density of the sebaceous gland units were also observed. In using the ear sebaceous model system it is important to standardize the site of biopsy in order to avoid sampling errors. The increase in ear sebaceous gland area from weaning to sexual maturity in the male hamster parallels the increase in flank organ area. This observation suggests that the ear and the flank organ sebaceous glands are comparable sebaceous models since they show a similarity in their response to the changing hormone levels during sexual maturation.