Dermatological effects of chronic exposure to 7,12-dimethylbenz[A]anthracene (DMBA) or N-methyl-N-nitrosoguanidine (MNNG) in swine.

Purpose: To determine whether chronic exposure to DMBA or MNNG in combination with or without UVB exposure would induce skin carcinomas in swine.

Methods: Eight gilts were exposed to 100 mJ of UVB in their left side, allowed to recuperate, and divided into two groups. Each gilt received identical high doses (DMBA 50 microM; MNNG 250 mM), low doses (DMBA 500 nM; MNNG 2.