Continuous Light Exposure as Factor in Pro-Senescent Liver Remodeling: Key Role of Melatonin Deficiency.

Circadian rhythm disruption is a risk factor for metabolic and age-associated diseases. The liver is a key target of such desynchronosis. The effect of chronic continuous light exposure and the corrective effect of melatonin on the liver status were investigated in rats. Desynchronosis mediated by melatonin deficiency was shown to induce the formation of a pro-senescent and metabolically dysfunctional liver phenotype. Melatonin administration significantly reduced the severity of the identified disorders and prevented statistically significant deviations in most of the parameters under study. The results, together with previous data on ultrastructural damage to hepatocytes and a negative impact of desynchronosis on lifespan, indicate that chronic continuous light exposure is a significant pro-gerontological factor and that melatonin is an effective agent for correcting the associated disturbances of liver homeostasis.