Determinants of muscle carnosine content

Abstract

The main determinant of muscle carnosine (M-Carn) content is undoubtedly species, with, for example, aerobically trained female vegetarian athletes [with circa 13 mmol/kg dry muscle (dm)] having just 1/10th of that found in trained thoroughbred horses. Muscle fibre type is another key determinant, as type II fibres have a higher M-Carn or muscle histidine containing dipeptide (M-HCD) content than type I fibres. In vegetarians, M-Carn is limited by hepatic synthesis of β-alanine, whereas in omnivores this is augmented by the hydrolysis of dietary supplied HCD’s resulting in muscle levels two or more times higher. β-alanine supplementation will increase M-Carn. The same increase in M-Carn occurs with administration of an equal molar quantity of carnosine as an alternative source of β-alanine. Following the cessation of supplementation, M-Carn returns to pre-supplementation levels, with an estimated t1/2 of 5–9 weeks. Higher than normal M-Carn contents have been noted in some chronically weight-trained subjects, but it is unclear if this is due to the training per se, or secondary to changes in muscle fibre composition, an increase in β-alanine intake or even anabolic steroid use. There is no measureable loss of M-Carn with acute exercise, although exercise-induced muscle damage may result in raised plasma concentrations in equines. Animal studies indicate effects of gender and age, but human studies lack sufficient control of the effects of diet and changes in muscle fibre composition.

Detoxification of aldehydes by histidine-containing dipeptides: From chemistry to clinical implications

“…In contrast, polymorphisms in the carnosinase gene, which affect plasma carnosine concentration after ingestion of carnosine, do not affect muscle carnosine content [85]. Supplementation with an isomolar amount of carnosine and its precursor β-alanine have been reported to increase muscle carnosine content by as much as 80% accompanied by improvements in ergometric performance [41, 86, 87]. …”

Chemical Composition and Sensory Evaluation of Fermented Tea with Medicinal Mushrooms

“…C-aminobutyric acid is a strong nerve inhibitory amino acid with sedation and hypnosis, anticonvulsive, and hypotensive functions [24]. Carnosine is a kind of natural antioxidant as well as an olfactory nerve sensor that was able to promote wound healing, especially during in surgical treatment [25].The contents of the nonprotein amino acids taurine, c-amino butyric acid and carnosine were 70.5, 156.8 and 115.8 mg/100 g in G.frondosa fermented tea; and 101.9, 58.1, 14.2 mg/100 g in Tianzhi-fermented tea, all were higher than those in common tea. Overall, the kinds and contents of amino acids in G. frondosa fermented tea were superior to those in Tianzhi fermented tea, except that in Tianzhi-fermented tea taurine content was 1.45 times higher than that in G. frondosa-fermented tea.…”

Reactive Carbonyl Species Scavengers—Novel Therapeutic Approaches for Chronic Diseases

“…Levels of carnosine are dramatically reduced in patients with diabetes mellitus [87, 88] and with Alzheimer’s disease [89], and modestly reduced in vegetarians, females, and elderly populations [90, 91]. In addition to RCS scavenging, carnosine acts as a physiological pH buffer, a hydroxyl radical scavenger, a redox active metal chelator, a stimulator of nitric oxide synthesis, and activator of carbonic anhydrase [92]…”