Increased Life Span and Decreased Weight in Hamsters Exposed to Cigarette Smoke

Abstract

Five groups of fifty-one 2-mo.-old male Syrian golden hamsters [Mesocricetus auratus] received three 10-min exposures to cigarette smoke/day, 4 days/wk, for the duration of their lives. Three of the groups were also chronically exposed to aerosols of chrysotile asbestos, cobalt oxide and nickel oxides, respectively. The 4th group received 12 weekly injections of 0.25 mg of diethylnitrosamine. The smoke-exposed groups lived significantly (P < .01) longer than their sham-exposed cohorts and untreated controls. Their mean body weights were significantly (P < .01) lower than in the sham-exposed groups. Delayed onset of amyloidosis and lower body weight in the smoke-exposed hamsters may have been responsible for their increased life spans. Cigarette smoke possibly affected the immune system of the animals, resulting in retardation of amyloidosis, a frequent cause of death in hamsters.