Central blockage of sympathetic nerves inhibits the abnormal vital signs and disturbance of the gut microbiota caused by continuous light exposure

Abstract

Background: Continuous light exposure increases sympathetic excitation in rats, leading to hypertension, left ventricular hypertrophy, and fibrosis. This study was aimed to investigate whether continuous light exposure causes destabilization of vital signs and gut microbiota (GM) in Sprague Dawley (SD) rats and whether clonidine hydrochloride (CH), a central sympathetic depressant drug, could prevent these changes. Methods: Eight-week-old male SD rats were divided into three groups with different interventions for 14 weeks: control group (CG), 2-mL pure water gavaged daily while on a normal 12-h light/dark cycle; continuous illumination group (CI), 2-mL pure water gavaged daily while receiving continuous exposure to light (300 lx); and drug administration group (DA), CH (10 μg/kg) gavaged daily while receiving continuous exposure to light (300 lx). Results: The results showed that blood pressure, heart rate, and body weight were significantly higher in the CI group than in the CG and DA groups (P Prevotella (genus level) > Prevotellaceae_bacterium (species level) were enriched in the CI group. The Muribaculaceae family was more abundant in the CG group than in the CI group. Conclusion: Sympathetic nerve inhibition restored the abnormal vital signs and GM changes under continuous light exposure.

Keywords

• Continuous light exposure
• Gut microbiota
• Sympathetic nerve
• Cardiovascular disease
• Circadian rhythm disruption