Consequences of low-intensity light at night on cardiovascular and metabolic parameters in spontaneously hypertensive rats.

Consequences of low-intensity light at night on cardiovascular and metabolic parameters in spontaneously hypertensive rats. Can J Physiol Pharmacol. 2019 Jun 28;: Authors: Rumanova VS, Okuliarova M, Molcan L, Sutovska H, Zeman M Abstract Circadian rhythms are an inherent property of physiological processes and can be disturbed by irregular environmental cycles, including artificial light at night (ALAN). Circadian disruption may contribute to many pathologies, such as hypertension, obesity and type 2 diabetes, but the underlying mechanisms are not understood. Our study investigated the consequences of ALAN on cardiovascular and metabolic parameters in spontaneously hypertensive rats (SHR), which represent an animal model of essential hypertension and insulin resistance. Adult males were exposed to a light (L)/dark (D) cycle of 12:12 h and the ALAN group experienced dim light at night (1-2 lux), either for 2 or 5 weeks. Rats on ALAN showed a loss of LD variability for systolic blood pressure (SysBP), but not for heart rate. Moreover, a gradual increase of SysBP was recorded over 5 weeks of ALAN. Exposure to ALAN increased plasma insulin and hepatic triglyceride levels. An increased expression of metabolic transcription factors, Pparα and Ppar, in the epididymal fat and a decreased expression of Glut4 in the heart was found in the ALAN group. Our results demonstrate that low-intensity ALAN can disturb BP control and augment insulin...
Source: Canadian Journal of Physiology and Pharmacology - Category: Drugs & Pharmacology Authors: Tags: Can J Physiol Pharmacol Source Type: research