Effects of vitamin B-6 deficiency and aging on pyridoxal 5′-phosphate levels and glycogen phosphorylase activity in rats

Autor: Stanley N. Gershoff, Elizabeth F. Cochary, James A. Sadowski
Rok vydání: 1991
Předmět:
Zdroj: The Journal of Nutritional Biochemistry. 2:135-141
ISSN: 0955-2863
Popis: Muscle, liver, brain, and plasma pyridoxal 5′-phosphate (PLP) concentrations and muscle, liver, and brain glycogen phosphorylase (GPase) activity were determined during vitamin B-6 deficiency and aging. Fischer 344, male rats, aged 15 weeks, and 6, 15, and 25.5 months at the end of the 12-week study, were divided into diet groups of ad libitum controls, deficienct or pair-fed controls. Plasma PLP levels in 25.5-month-old control rats were lower (P ≤ 0.05) than the other three age groups which were slightly, but not significantly different from each other. Plasma PLP of deficient rats was dramatically decreased (P ≤ 0.05) in all age groups. Muscle PLP was decreased (P ≤ 0.05) in all vitamin B-6 deficient rats. Liver and brain PLP concentrations were decreased (P ≤ 0.05) in 15 week, 6 month, and 15 month deficient rats only. Tissue PLP levels were correlated (P ≤ 0.01) with plasma PLP. Vitamin B-6 deficiency resulted in decreased glycogen phosphorylase activity (P ≤ 0.05) in muscle, liver, and brain of 15 week rats, and in muscle and liver of 6 month rats. Reduction in food intake did not account for the reported changes during vitamin B-6 deficiency. A significant correlation between tissue glycogen phosphorylase activity and tissue PLP levels was observed. Vitamin B-6 deficiency significantly lowered tissue PLP and phosphorylase activity, but the decrease in each was less marked with increasing age.
Databáze: OpenAIRE