Effects of Recurrent Stress and a Music Intervention on Tumor Progression and Indices of Distress in an MNU-induced Mammary Cancer in Rats

Abstract

The present research examined biological and behavioral effects of recurrent stress, music exposure, and a sound ("noise") control on mammary tumor progression and indices of distress in female rats. All animals were injected with 1-methyl-1 nitrosourea (MNU) to induce mammary tumors. The present research was a 2 x 3 design with stress/no stress and music/noise/no music exposure as the independent variables. The biological variables were: day of first tumor detection, tumor multiplicity, tumor weight, tumor growth, adrenal gland weight, spleen weight, serum corticosterone, and body weight. The behavioral variables were: center time, horizontal activity, and vertical activity, ultrasonic vocalizations, and food consumption.