Keiichirou Ueshima

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The role of capsaicin-sensitive afferent neurons in acid-induced HCO3- secretion was investigated in the duodenum of anesthetized rats. The proximal duodenum was perfused with saline (pH 4.5), the pH of perfusate and the transmucosal potential differences were continuously monitored, and HCO3- output was determined by pH change. Under these conditions,(More)
The relationship of gastric hypermotility to mucosal hemodynamics, lipid peroxidation and vascular permeability changes was investigated in the pathogenesis of indomethacin-induced gastric lesions in rats. Subcutaneous administration of indomethacin (25 mg/kg) produced an increase in both the amplitude and frequency of stomach contraction from 30 min after(More)
We have examined the effect of orally administered capsaicin on gastric motility in the rat to investigate a possible relationship between motility change and cytoprotection induced by this agent. Capsaicin, given orally (1-30 mg/kg), dose-dependently inhibited hemorrhagic band-like lesions induced by ethanol (60% in 150 mM HCl). This protection was(More)
BACKGROUND/AIMS Capsaicin-sensitive sensory neurons are important in protecting the stomach against damage. This study investigated the role of these sensory neurons in the healing of gastric lesions. METHODS Rats fasted for 18 hours were given 1 mL of 0.6N HCl orally for induction of gastric lesions; they were then fed normally from 1 hour later. On(More)
The role of endogenous sulfhydryls (SH) in the healing of HCl-induced gastric injury was investigated in the rat. The animals fasted for 18 h were given 1 ml of 0.6 N HCl by gavage, and they were fed normally from 1 h later and killed various days after HCl treatment. Gastric lesions induced by HCl healed to quiescent states within 7 days both(More)
We used capsaicin as a selective probe for sensory neuronal mechanisms and examined in rats whether defunctionalization of the sensory nerves caused duodenal ulcers in the presence of acid hypersecretion. Chemical deafferentation was performed by subcutaneous injection of capsaicin for 3 days (total dose: 100 mg/kg) 2 weeks before the experiment. This(More)
Exposure of rat stomach to 1 M NaCl reduced the transmucosal potential difference (PD) followed by an increase of luminal pH and gastric mucosal blood flow (GMBF). Desensitization of capsaicin-sensitive afferent neurons significantly mitigated the increase in GMBF without affecting PD and pH responses. Mucosal application of capsaicin increased GMBF with no(More)
We set up a new system for measuring the gastroduodenal HCO3- responses using pH change and potential difference (PD) in the anesthetized rat. The stomach or the proximal duodenum was perfused at the flow rate of 0.7 mL/min with saline (pH 4.5), the pH of the perfusate and PD were continuously monitored, and HCO3- output was determined by back-titrating the(More)
The role of mucosal sulfhydryl (SH) in the pathogenesis of indomethacin-induced gastric lesions was investigated in rats. Indomethacin (25 mg/kg, s.c.) caused high-amplitude gastric contractions, resulting in linear hemorrhagic lesions in the corpus mucosa within 4 hr, but did not induce any changes in the mucosal SH levels. These lesions were prevented(More)
Pathogenesis of duodenal ulcers induced by diethyldithiocarbamate (DDC), a superoxide dismutase (SOD) inhibitor, was investigated in the rat. Repeated s.c. administration of DDC (750 mg/kg) every 12 hr induced duodenal ulcers in the fed rats, and the severity of the ulcers reached the maximum after three injections. DDC not only reduced basal acid output(More)