Response of murine cutaneous nerves to skin painting with methylcholanthrene

A saturated solution of 20‐methylcholanthrene in benzene was applied to the ear and trunk of 59 BALB mice. The effects upon cutaneous innervation were compared with that of 50% turpentine in acetone (13 mice) and of skin abrasion with sandpaper (11 mice). Silver impregnation techniques showed that the carcinogentreated epidermis was invaded by nerve fibers whose number was related to the degree of epidermal hyperplasia, but not to the period of treatment or to the animals' age at the time of first painting. Hair follicles showed changes in the size, number and length of nerve endings. Growth of cutaneous nerves was already evident on the fourth day of exposure to methylcholanthrene. Turpentine elicited only a slight neural reaction after 60 days; and the sandpaper treatment was without effect.