Aim: The impact of the sympathetic nervous system (SNS) on the regulation of circadian rhythm and physiological functions is still not clear. Previous studies have found that essence of chicken (EC) supplementation facilitated the physiological adaption and circadian resetting in rats subjected to jet lag. Herein, the effects of SNS on the circadian clock and the hypothesis that EC-induced acceleration of circadian resetting is dependent on the SNS are investigated.
Main methods: Male Wistar rats with superior cervical ganglionectomy (SCGx) were used to investigate the role of the SNS in circadian rhythm and physiological functions. SCGx rats were further fed with or without EC-containing diet for 2 weeks and subjected to artificial jet lag.
Key findings: Loss of SNS did not affect the circadian rhythm both in the hypothalamic suprachiasmatic nuclei (SCN) and peripheral clocks, including the liver and heart. The serum lipid levels were increased significantly in SCGx rats, together with the up-regulation of lipogenic gene expression in the liver and slight effect on serum hormones. The quicker resetting process of the clock genes in peripheral tissues of EC-fed rats was abolished after SCGx. In contrast, the phase shift of serum melatonin and corticosterone were faster in EC-fed rats, compared to that of control rats.
Significance: The SNS controls different aspects of physiological functions, and it has little effect on circadian system under normal light/dark condition. The effects EC on peripheral circadian synchrony and physiological functions were dependent on, at least partly, through the regulation of sympathetic nerve function.
Keywords: Circadian clock; Essence of chicken; Physiological function; Superior cervical ganglionectomy; Sympathetic nervous system.
Copyright © 2018. Published by Elsevier Inc.