Adding potassium nitrate (KNO3) to the diet improves the physiological properties of mammalian muscles (rebuilds weakened muscle, improves structure and functionality). The aim of this study was to investigate the effect of KNO3 supplementation in a mouse model. BALB/c mice were fed a KNO3 diet for three weeks, followed by a normal diet without nitrates. After the feeding period, the Extensor digitorum longus (EDL) muscle was evaluated ex vivo for contraction force and fatigue. To evaluate the possible pathological changes, the histology of EDL tissues was performed in control and KNO3-fed groups after 21 days. The histological analysis showed an absence of negative effects in EDL muscles. We also analyzed 15 biochemical blood parameters. After 21 days of KNO3 supplementation, the EDL mass was, on average, 13% larger in the experimental group compared to the controls (p < 0.05). The muscle-specific force increased by 38% in comparison with the control group (p < 0.05). The results indicate that KNO3 has effects in an experimental mouse model, showing nitrate-diet-induced muscle strength. This study contributes to a better understanding of the molecular changes in muscles following nutritional intervention and may help develop strategies and products designated to treat muscle-related issues.
Keywords: BALB/c mouse model; athletic performance; muscle force; muscle histology; muscle recovery; nitrates; nitric oxide; potassium nitrate; sarcopenia.