Effect of Audiogenic Stress upon Methylcholanthrene-induced Carcinogenesis in Mice.

DBA/1 (audiogenic seizure-susceptible) and A/Jax (seizure-resistant) mice were subjected to bell-ringing sound and an approximate 80-90 per cent effective carcinogen ic dose of 20-methylcholanthrene and observed for time of tumor induction and ulti mate fate. There was a delay in the time of tumor induction (latent period) in DBA/1 mice subjected to audio stimulus as compared with DBA/1 controls, whereas A/Jax mice were unaffected. Despite the delayed tumor induction in sound-stimulated DBA/1 mice, their survival time was the same as comparable controls. It is believed that, once induced, the tumor cell growth was stimulated by the sound stress exposure. No significant differences in carcinogenesis were noted when cortisone was adminis tered in lieu of sound stress. The addition of cortisone to sound stress exposure signifi cantly reduced the tumor induction in the DBA/1 mice (58 per cent), whereas tumor induction in A/Jax mice was 100 per cent, a slight increase over A/Jax controls.