Effect of vitamin C on glucose metabolism in partial and total paradoxical sleep-deprived male wistar rats

Abstract

Background: Chronic sleep deprivation is associated with increases in oxidative stress and impaired glucose homeostasis. The effect of vitamin C on glucose metabolism and oxidative stress in sleep deprived animals was investigated in this study.

Method: Thirty male Wistar rats (150-200 g) divided into six groups as control; control + vitamin C (CC); partial sleep deprived (PSD); partial sleep deprived + vitamin C (PSDC); total sleep deprived (TSD); and total sleep deprived + vitamin C (TSDC) were used. Paradoxical sleep deprivation was by the modified multiple platform for 20 hours daily in PSD and PSDC or for 24 hours daily in TSD and TSDC for 7 days. Vitamin C (300mg/kg, daily) was administered to animals in CC, PSDC and TSDC groups. After the 7 days SD and/or vitamin C treatment, blood samples were obtained for fasting blood glucose, lactate, Malondialdehyde (MDA), Superoxide dismutase (SOD) and catalase. Muscle and liver samples were obtained for glycogen determination while hexokinase and glucose-6-phosphatase activities were determined in the liver sample.

Results: Body weight decreased significantly in TSD rats; the percentage weight loss was however reduced in TSDC. Serum MDA increased in PSD and TSD compared with control; but lower in PSDC and TSDC compared with PSD and TSD, respectively. Catalase activity was decreased in TSD and TSDC. Fasting blood glucose level, plasma lactate and muscle glycogen were reduced in TSD and TSDC. Hepatic glycogen increased in TSD but decreased in TSDC. Glucose 6-phosphatase activity decreased in PSD but increased in TSD; also, the activity decreased in TSDC with no difference in PSDC compared with control. Hexokinase activity was decreased in TSD but increased in TSDC.

Conclusion: Partial sleep deprivation had no effect on glucose metabolism but total sleep deprivation caused derailment in glucose metabolism which was not reversed by vitamin C despite reductions in oxidative stress.

Keywords: Sleep deprivation, Glucose metabolism, Vitamin C, Oxidative stress, Rats