EFFECT OF LIGHT REGIMENS AND MELATONIN ON HOMEOSTASIS, LIFE SPAN AND SPONTANEOUS TUMORIGENESIS IN MALE RATS
The effect of various light regimens - standard, 12 firs light:12 firs darkness, natural lighting in the North-West of Russia and constant illumination - on homeostasis, life span and spontaneous tumorigenesis has been studied in male rats. It was shown that constant exposure or natural lighting involved accelerated aging as evaluated by coefficient of homeostatic stability and survival curves shifting to the left. Constant illumination was followed by a significantly faster spontaneous tumorigenesis as compared with standard lighting. Nocturnal administration of melatonin with drinking water (10mg/l) prevented the adverse effects of constant and natural lighting on homeostasis and inhibited spontaneous tumorigenesis, particilarly, that in the hemopoietic system.