ORAL PRESENTATION: Effects on metabolism due to circadian desynchronization in a murine model of chronic jet-lag.

ROTA ROSANA; ALZAMENDI ANA; PLANO SANTIAGO; REGUEIRA NICOLE; GIOVAMBATTISTA ANDRES; GOLOMBEK DIEGO ANDRÉS.; CHIESA JUAN JOSE; AIELLO IGNACIO; CASIRAGHI LEANDRO

COLONIA

Simposio; XV Latin American Symposium on Chronobiology; 2019

Chronic circadian misalignment due to altered photic entrainment lead to several physiological disruptions. By exposing C57BL/6J mice to 6-h advances every 2 days of the 12 h light: 12 h dark (LD) cycles (i.e., chronic jet-lag, CJL), we found behavioral desynchronization together with increased body weight gain, with similar daily food intake when compared to mice entrained to LD cycles. Mice under CJL also showed increased adipose tissue and adipocyte size, as well as higher levels of plasma triglycerides. Abnormal weight gain under CJL was not observed in mice having voluntary access to running wheel, which showed entrained behavioral rhythms, as well as when food intake was restricted to darkness. Then, we studied glucose circadian homeostasis, founding dampened glucose rhythms under ad libitum conditions (with higher glycaemia at darkness), as well as incipient reduced glucose tolerance at forced desynchronized ?night? in a hyperglycemic clamp test. Triglycerides did not evidence rhythmicity neither under LD, nor under CJL. We hypothesized that mistimed glucose usage (as well as loss of insulin sensitivity, not measured in this work), lead to altered glucose homeostasis. This loss of circadian homeostasis in energy balance could emerge from desynchronization between behavioral rhythms, caloric intake, and caloric expenditure.