Effects of inhibitors of hydrogen sulphide synthesis on rat colonic motility

摘要: BACKGROUND AND PURPOSE The role of hydrogen sulphide (H2S) as a putative endogenous signalling molecule in the gastrointestinal tract has not yet been established. We investigated effect D,L-propargylglycine (PAG), an inhibitor cystathionine γ-lyase (CSE), amino-oxyacetic acid (AOAA) and hydroxylamine (HA), inhibitors β-synthase (CBS) on rat colonic motility. EXPERIMENTAL APPROACH Immunohistochemistry, H2S production, microelectrode organ bath recordings were performed samples without mucosa submucosa to investigate motility. KEY RESULTS CSE CBS immunolocalized colon. was endogenously produced (15.6 ± 0.7 nmol·min−1·g−1 tissue) its production strongly inhibited by PAG (2 mM) AOAA (2 mM). caused smooth muscle depolarization increased spontaneous motility. still recorded after incubation with tetrodotoxin (TTX, 1 µM) or Nω-nitro-L-arginine (L-NNA, 1 mM). transient (10 min) increase In contrast, HA (10 µM) ‘nitric oxide-like effect’, hyperpolarization relaxation, which antagonized 1H-[1,2,4]oxadiazolo[4,3-α]quinoxalin-1-one (ODQ, 10 µM). Neither nor induced inhibitory junction potentials modified PAG. CONCLUSIONS IMPLICATIONS demonstrated that is effectively blocked production. Our data suggest enzymatic regulates motility therefore might be third gaseous tract. However, possible non-specific effects should considered.