Journal of physiology and pharmacology : an official journal of the Polish Physiological Society
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J. Physiol. Pharmacol. · Feb 2012
Hydrogen sulfide-induced colonic mucosal cytoprotection involves T-type calcium channel-dependent neuronal excitation in rats.
Hydrogen sulfide (H(2)S) is generated from L-cysteine by certain enzymes including cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS), and causes excitation of nociceptors mainly via activation of Ca(v)3.2 T-type Ca(2+) channels in the peripheral tissue, facilitating somatic and colonic pain. Here, we investigated whether sensory nerves and Ca(v)3.2 are involved in the H(2)S-induced mucosal cytoprotection against 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. Colitis was evaluated 3 days after intracolonic (i.c.) TNBS in the rat. ⋯ Ca(v)3.2 protein was upregulated in DRG 1 day after i.c. TNBS in rats, while CSE, but not CBS, protein was downregulated in the colon. Our findings suggest that luminal H(2)S causes excitation of sensory nerves most probably by activating Ca(v)3.2 T-type Ca(2+) channels that are upregulated in the early stage of colitis, leading to colonic mucosal cytoprotection in rats.