Inhibitory effects of 13-cis-retinoic acid on human sebaceous glands.

The effects of 13-cis-retinoic acid, which is clinically very effective in the treatment of severe acne, on sebaceous glands in humans was studied by means of histology, planimetry, and autoradiography. Histologically and planimetrically, one finds a marked decrease of size of sebaceous glands of up to 90% of the pretreatment values after 12 weeks of treatment. Additionally, the ratio of the so-called "differentiating cell pool (DCP)" vs. the so-called "undifferentiating cell pool (UCP)" changed from 2:1 to 1:7, probably indicating a disturbance of differentiation (lipid-production) of sebocytes. The labeling index of sebocytes also regressed significantly under therapy with 13-cis-retinoic acid.