ABSTRACT
Muscle carnosine is an intracellular buffer. The intake of ß-alanine, combined with carbohydrate and protein, enhanced carnosine loading in human muscle. The aim of the present study was to examine if muscle carnosine loading was enhanced by ß-alanine intake and co-ingestion of glucose in male rats. Thirty-six male rats were divided into three groups and supplemented for four weeks: ß-alanine (ßA group, 1.8% ß-alanine in drinking water), ß-alanine and glucose (ßAGL group, 1.8% ß-alanine and 5% glucose in drinking water), and control (C group, drinking water). During the supplementation period, rats were exercised (20 m·min-1, 10 min·day-1, 4 days·week-1 for 4 weeks). Muscle carnosine concentration was quantified in soleus (n = 12) and rectus femoris (n = 6) muscles using high-performance liquid chromatography. In soleus muscle, carnosine concentration was 2.24 ± 1.10, 6.12 ± 1.08, and 6.93 ± 2.56 mmol/kg dw for control, ßA, and ßAGL, respectively. In rectus femoris, carnosine concentration was 2.26 ± 1.31, 7.90 ± 1.66, and 8.59 ± 2.33 mmol/kg dw for control, ßA, and ßAGL respectively. In each muscle, ßA and ßAGL resulted in similar carnosine increases compared to the control. In conclusion, ß-alanine intake for four weeks, either alone or with glucose co-ingestion, equally increased muscle carnosine content. It appears that the potential insulin response to fluid glucose intake does not affect muscle carnosine loading in male rats.
