Factors influencing the incidence of epidermal methylcholanthrene tumors in mice treated with cortisone. III. Studies of the hair follicular cycle (skin cycle) in relation to the incidence of tumors after cortisone administration

[Skincycle of a new spontaneous mutant (Nackig) with abnormal hair keratinization in the mouse (author's transl)]

The pathomorphological and pathophysiological reactions of the first skincycle of the mutant (Ng) were histologically investigated. 1. During the hair growth disturbances as the result of imperfect keratinisation changes of the morphology and function of different skin areas could be observed. 2. The developments of abnormal thinner hair growth were correlated to hyperorthokeratotic, inter-respectively intrafollicular hyperplasia of the epidermis and to infraseboglandular hypoplasia of the follicles. 3. The hyper- and hypoplasia of the epidermis corresponded with a functional pseudohypo- and pseudohypertrophy of the cutis. 4. During the skincycle the perifollicular epithelium ranged from the inter- to intrafollicular skin areas. The inter- and intrafollicular epidermal sections varied simultaneously. 5. These results are important for the understanding of some pathomorphological and pathophysiological reactions of skin compartments of man.