Calcium handling in muscle

Buffering is not the only proposed mechanism in muscle. In skinned fibres from human vastus lateralis, carnosine at 8 and 16 mmol/L raised the calcium sensitivity of the contractile apparatus. The pCa50 shifted by 0.07 to 0.12 units, which the authors equate to about a 20 per cent rise in force at a given calcium level. Carnosine also increased caffeine-induced calcium release. The authors caution that the release effect may not occur in the living muscle (Dutka, Lamboley, McKenna, Murphy and Lamb, Australian Physiological Society).

Everaert and Derave write that in vitro data on buffering and calcium handling could partly explain the effect of beta-alanine on performance, and that more in vivo human work is needed (Royal Society of Chemistry, 2015). Histidine dipeptides have also been described as regulators of excitation-contraction coupling in heart muscle.

See Exercise and muscle for the trials.