Nicotinic Acid Improves Endurance Performance of Mice Subjected to Treadmill Exercise

Robert Ringseis,Gaiping Wen,Anna M Beer,Denise K Gessner,Karsten Krüger,Klaus Eder,Yvonne Albrecht,Erika Most

doi:10.3390/metabo10040138

Abstract

Recently, administration of nicotinic acid (NA) at a pharmacological dose was found to induce a similar change in the muscle´s contractile and metabolic phenotype as observed in response to endurance exercise. Thus, the hypothesis was tested that combined NA administration and endurance exercise promotes the adaptation of muscle to regular exercise and improves the endurance performance to a greater extent than exercise alone. Thus, 30 adult mice were randomly divided into three groups of 10 mice/group. The control and the exercise (EX) group received an adequate NA diet, while the EX + NA group received a high NA diet. Mice of the EX and the EX + NA group were subjected to a treadmill endurance exercise program five times/week during the experimental period of 42 days. At day 41, endurance performance was greater in the EX + NA group than in the control and the EX group (p < 0.05). Mice of the EX + NA group had a higher type IIA (+60%) and a lower type IIB (−55%) fiber percentage in gastrocnemius (GN) muscle than control mice (p < 0.05), while the type I fiber percentage in GN muscle tended to be increased (+100%) in the EX + NA group compared to the control group (p = 0.051). In the EX + NA group, glycogen concentration (+15%) and mRNA levels of two glycolytic (+70–80%) and two glycogenolytic enzymes (+80–120%) in GN muscle were increased compared to the control group (p < 0.05). In conclusion, feeding a high NA diet induces changes in skeletal muscle fiber composition and improves endurance performance of mice subjected to regular endurance exercise.

Highlights

Nicotinic acid (NA) belongs to the B-complex of vitamins which share as a common characteristic to act as precursors of specific coenzymes (NAD+ and NADP+ ) essentially required in intermediary metabolism in all tissues
+ NA group compared to the control group and the EX group (Figure 1B; p < 0.05)
The NA dose ingested from the high NA diet caused a 7- to 10-fold elevation in the plasma NAM concentration in mice of the EX + NA group compared to mice of the other groups

Summary

Introduction

Nicotinic acid (NA) belongs to the B-complex of vitamins which share as a common characteristic to act as precursors of specific coenzymes (NAD+ and NADP+ ) essentially required in intermediary metabolism in all tissues Apart from this physiological function of NA, NA is well known to exhibit pronounced blood lipid-modulating activities, such as lowering of triacylglycerols (TAG), at high doses (in humans 2–6 g/day) [1]. Recent research dealing with lipid-modulating effects of NA has focused on skeletal muscle which does not express the NA receptor hydroxycarboxylic acid receptor 2, but owing to its great mass and extensive utilization of fatty acids as energy source affects plasma TAG concentration In this context the observation from a recent study that feeding NA at pharmacological levels to insulin-resistant obese rats affects the contractile and metabolic phenotype of skeletal muscle is remarkable [3]. The NA-induced change in muscle contractile phenotype of obese rats resulted in a more oxidative metabolic phenotype as evidenced by higher muscle expression of genes involved in fatty acid utilization and oxidative phosphorylation [3]

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