Methylglyoxal is an intracellular TRPA1 agonist.

<p>(A) Application of MG evokes concentration-dependent [Ca²⁺]_i-responses in CHO cells expressing mouse or human TRPA1. (B) MG (0.5 mM) elicits inward currents with the characteristic rapid onset and inactivation in the presence of 2 mM Ca²⁺ (top panel). In Ca²⁺-free solutions (1 mM EGTA) the inward current grew more slowly and addition of Ca²⁺ produced the typical current surge followed by a rapid inactivation of the current (bottom panel). (C) MG rapidly activates TRPA1 in excised inside-out patches, with a markedly higher potency than when applied extracellularly (D, compare with A). (E) The current voltage relationship in membrane patches containing several channels demonstrated a reversal potential close to 0 mV and channel block or inactivation at positive membrane potential. (F) Current-voltage relationship for a single channel in an inside-out patch stimulated with MG.