Features of the circadian rhythm in the size of the mitochondria of rat hepatocytes under conditions of dark deprivation and chronic alcohol intoxication

Abstract

BACKGROUND: Circadian rhythms of body functions and processes are normally strictly coordinated with each other and environmental factors, which ensures optimal maintenance of the functioning of body organs and systems. However, no studies have assessed the circadian rhythms of hepatocyte organelles under experimental conditions. AIM: To assess the daily dynamics of the cross-sectional area of rat hepatocyte mitochondria under conditions of dark deprivation, chronic alcohol intoxication, and their combination. MATERIALS AND METHODS: The study analyzed 80 male and 80 female Wistar rats, divided into 4 groups of each sex: group 1 was kept under a fixed light regimen, group 2 under dark deprivation, group 3 in the same conditions as the control group but were subjected to chronic alcohol intoxication, and group 4 under dark deprivation and chronic alcohol intoxication. Liver samples, after fixation and wiring, were analyzed under a transmission electron microscope. Micromorphometric methods were used to assess the mitochondrial apparatus of hepatocytes. RESULTS: In rat hepatocytes from the experimental groups of both sexes, the circadian rhythm of the cross-sectional area of the mitochondria with similar parameters was detected. Dark deprivation and chronic alcohol intoxication, acting both separately and together, resulted in the restructuring of mitochondrial size distribution, which was more pronounced in males. CONCLUSION: The study indicates that the circadian rhythm of mitochondrial size is dependent on the lighting regimen and toxic effects of ethanol and its metabolites. The size ranges of the mitochondria in the hepatocytes of females, compared with those of males, are more resistant to the effects of dark deprivation and alcohol intoxication.