Carnosine
Carnosine, a metabolite. β-Alanyl-L-histidine dipeptide, highly concentrated in fast-twitch skeletal muscle (~20–40 mmol/kg dry weight) and… Oral half-life 0 h.
β-Alanyl-L-histidine dipeptide, highly concentrated in fast-twitch skeletal muscle (~20–40 mmol/kg dry weight) and olfactory bulb. Intramuscular roles: proton buffer (pKa 6.83 — ideal for pH-drop during high-intensity contraction), reactive carbonyl / metal ion chelator, and pH-independent Ca²⁺ sensitiser in myofibrils. Orally, intact carnosine is rapidly cleaved by serum carnosinase (CN1/CNDP1) and tissue carnosinase (CN2) to β-alanine + histidine within minutes of absorption. Therefore oral carnosine itself is a poor way to raise muscle carnosine — oral β-alanine is the rate-limiting precursor and the evidence-based route.
Pharmacokinetics
- Oral — t½ 1 min · F 5%
Related compounds
- β-Alanine — synergistic
Sources: PMID:23479117