Dual modulation of the tension of isolated gastric artery and gastric mucosal circulation by hydrogen sulfide in rats.
To clarify roles of H2S in regulation of gastric circulation, we investigated effects of NaHS, a H2S donor, on tension of isolated rat gastric artery and gastric mucosal blood flow in rats. In the precontracted ring preparations, NaHS caused contraction and relaxation at low and high concentrations, respectively. The NaHS-induced vasorelaxation was only partially blocked by glibenclamide, a K+ (ATP) channel inhibitor. The contractile activity of NaHS disappeared by removal of the endothelium or by inhibition of nitric oxide synthase and the endothelium-derived hyperpolarizing factor (EDHF) pathways. Intravenous injection of NaHS caused transient increase followed by decrease in gastric mucosal blood flow in rats. Collectively, in the gastric artery, NaHS appears to cause relaxation through both K+ (ATP) channel-dependent and -independent pathways and contraction through inhibition of NO and EDHF pathways. Together with the in vivo results, our study implies that H2S plays multiple complex roles in regulation of gastric circulation.
Kubo
S
S
Division of Physiology and Pathophysiology, School of Pharmacy, Kinki University, 3-4-1 Kowakae, Higashi-Osaka, 577-8502, Japan.
Kajiwara
M
M
Kawabata
A
A
D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000502:physiology*; D001685:Biological Factors / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology; D005753:Gastric Mucosa / Q000098:blood supply* / Q000187:drug effects / Q000502:physiology*; D005905:Glyburide / Q000494:pharmacology; D006862:Hydrogen Sulfide / Q000494:pharmacology*; D066298:In Vitro Techniques; D054086:KATP Channels / Q000037:antagonists & inhibitors; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors; D026902:Potassium Channel Blockers / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D013270:Stomach / Q000098:blood supply* / Q000187:drug effects
D001685:Biological Factors; D054086:KATP Channels; D026902:Potassium Channel Blockers; C067410:endothelium-dependent hyperpolarization factor; D052250:Nitric Oxide Synthase Type III; D005905:Glyburide; D006862:Hydrogen Sulfide