• Biomolecules & Therapeutics
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• 제4권2호
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• pp.111-121
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• 1996

Antiulcer effects of Artemisia herba extract (DA-9601) were evaluated in various types of experimental gastric ulcer induced in rats. And the effects of DA-9601 on mucus, basal and stimulated gastric acid secretion were also investigated in rats. DA-9601 (12.5∼400 mg/kg, p.o.) prevented the formation of gastric ulcers induced by 60% EtOH in 150 mM HC1, restraint water immersion stress, platelet activating factor (PAF), aspirin in 150 mM HCI with Pylorus-ligation and indomethacin. DA-9601 (4∼400 mg/kg, p.o.) significantly accelerated the healing rate of acetic acid-induced gastric ulcer and significantly stimulated mucus secretion in a dose-dependent manner. DA-9601 (20∼200 mg/kg, i.d.), however, did not inhibit basal gastric acid secretion in pylorus ligated rats and DA-9601 (200 mg/kg, i.d.) failed to influence histamine-, pentagastrin- and carbachol- stimulated gastric acid secretion. These results suggest that DA-9601 has inhibitory action on gastric lesion and ulceration through increasing mucus secretion in the stomach of rats without influencing basal and stimulated gastric acid secretion.

• 대한약리학회지
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• 제31권1호
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• pp.75-84
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• 1995

NO의 위산분비에 대한 작용을 규명하기 위하여 분리한 토끼위선세포에서 hypoxia/reoxygenation과 acidosis후 위산분비와 NO synthase 활성을 측정하였다. 분리한 위선세포에 30분의 hypoxia와 1시간의 reoxygenation을 주었으며, acidosis를 위하여 배지의 pH를 6.0과 4.0으로 변화시켜 실험하였다. 위산분비는 위선세포 내와 외의 $[^{14}C]-aminopyrine$ 축적비율로 측정하였으며, NO synthase 활성은 NO의 전구물질인 $[^{14}C]L-arginine$으로부터 $[^{14}C]-citrulline$으로의 전환율로 결정하였다. 결과로서 dibutyryl cAMP는 농도 의존적으로 위산분비를 촉진시켰으나 NO synthase 활성엔 영향을 주지 않았다. Hypoxia/reoxygenation은 기초 및 자극 위산분비를 억제하였으며 acidosis에 의해 위산분비억제는 더욱 심화되었다. Constitutive NO synthase 활성 역시 hypoxia/reoxygenation과 acidosis에 의해 억제되었다. 결론적으로 hypoxia/reoxygenation과 acidosis 같은 위점막의 병적상태는 위산분비와 NO 유리를 모두 억제하나, 기초상태의 위선에서 dibutyryl cAMP에 의한 위산분비 촉진에 대한 NO의 직접적인 작용은 확인되지 않았다.

• Journal of Ginseng Research
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• 제25권4호
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• pp.141-149
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• 2001

The effect of ginseng on gastric ulcer and gastric acid secretion was investigated in pylorus-ligated rats. Methods: Sprague-Dawley strain rats were used after 24 hours fast. Pylorus-ligation was performed under light ether anaesthesia, then gastric mucosal damage was evoked in conscious pylorus-ligated rats by the administration of subcutaneous (s.c.) indomethancin (20mg/kg), s.c. histamine (150mg/kg) or by pylorus-ligation (Shay ulcer). Ginseng was given by intragastric (i.g.) or intraperitoneal (i.p.) route simultaneously with the ulcerogens. Rats were killed after 3h (indomethacin) and histamine models) or after 18h (Shay ulcer), when the gastric secretory responses, the number and severity of gastric mucosal lesions and mucosal mucus content deetermined. the effect of i.p. ginseng on basal gastric acid secretion and on gastric acide secretion in indomethacin (20mg/kg, s.c.)-treated rats was also investigated in urethane anesthetized rats. Gastric acid secretion was measured by flushing of the gastric lumen with saline every 15min through an oesophageal cannula. Results: In conscious pylorus-ligated rats, i.g. ginseng(12.5-50mg/$m\ell$; 50-200mg/kg) protected against gastric mucosal lesions evoked by s.c. indomethacin or s.c. histanmine in the d3-h pylorus-lighted rat, withoutmodifying gastric acid secretory responses. Ginseng given i.p. (150 or 200mg/kg) did not reduce the gastric lesions produced by histamine or by ligating the pylorus (Shay ulcer) Ginseng given orally in 50mg/$m\ell$ (200mg/kg) increased gastric mucus secretion in saline- and indomethacin-treated conscious pylorus-ligated rats. In anaesthetized rats ginseng (50 or 200mg/kg) did not modify basal gastric acid secretion or gastric acid secretion in the indomethacin-treated rats. Conclusions: ginseng given orally exerts gastroprotective effects in the rat stomach. Such anti-ulcer effect does not involve changes in gastric acid secretory responses. In addition, ginseng possesses stimulatory effect on gastric mucus secretion, which could be one mechanism by which the compound exerts its antiulcer effect. Our data are in favor for a beneficial effect for topically applied ginseng on the gastric mucosa.

• The Korean Journal of Physiology
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• 제20권2호
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• pp.249-256
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• 1986

The present study was performed to investigate a possible influence of the adrenergic nervous system on pancreatic exocrine secretion stimulated by intraduodenal acid perfusion. Pancreatic secretion was collected in rats anesthetized with urethane after 24 hours fasting. The duodenal lumen was perfused (0.2 ml/min) with HCI solution in a concentration of 0.005, 0.01, 0.02, 0.05 or 0.1 N When the volume of panceratic juice secreted for IS min became constant phentolamine (1 mg/kg), $noradrenaline\;(10\;{\mu}g/kg),\;Propranolol\;(1\;mg/kg),\;and \;isoproterenol\;(1\;{\mu}g/kg)$ were administered through the jugular vein in bolus. The secretory volume and protein output were measured in the pancreatic juice collected for 15 min. 1) HCI, perfused intraduodenally in graded concentrations from 0.005 N to 0.1 N, increased the pancreatic secretory volume and protein output dose-dependently. 2) In the basal state as well as in the stimulated state by the duodenal acid perfusion, phentolamine increased the pancreatic secretory volume and protein output while propranolol inhibited the volume and protein output. 3) In the basal state, noradrenaline did not change the pancreatic secretory volume but increased the protein output while isoproterenol increased both of the secretory volume and the protein output. These results strongly suggest that ${\alpha}-adrenoceptors$ in the rat pancreas exert an inhibitory influence on the pancreatic exocrine secretion including volume and protein output in the basal state as well as in the stimulated state by the intraduodenal acid perfusion while ${\beta}-adrenoceptors$ play a stimulatory role in the pancreatic exocrine secretion. However, in the physiological situation, adrenergic excitation may stimulate the protein output through ${\beta}-adrenoceptors$ without change in the secretory volume in the rat pancreas.

• The Korean Journal of Physiology
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• 제23권1호
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• pp.119-127
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• 1989

This study was undertaken to investigate the effect of medial amygdala on the gastric acid secretion and plasma gastrin concentration in the rats with chronic gastric fistula. After the medial nucleus of amygdala was damaged bilaterally by radiofrequency a. c. through stereotaxically inserted electrodes, the gastric juice was collected in the basal and histamine-stimulated states for 1 hour. The gastric juice was also collected while the medial nucleus of amygdala was stimulated with biphasic square wave in the both states. After the collection of the gastric juice, blood samples were drawn from the abdominal aorta for the radioimmunoassay of plasma gastrin. The results were as follows: 1) The damage of the medial amygdala significantly decreased the gastric juice volume and the acid output in the histamine-stimulated state. 2) The electrical stimulation of the medial amygdala significantly increased the gastric juice volume and the acid output in the histamine-stimulated state, and the acid output in the basal state. 3) The damage of the medial amygdala significantly decreased the plasma gastrin concentration but the electrical stimulation of the medial amygdala did not affect the plasma gastrin concentration. It is therefore suggested that the medial amygdala has a facilitatory influence on the histamine-stimulated gastric acid secretion in rats, and the influence may not be attributed to gastrin release.

• The Korean Journal of Physiology
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• 제22권2호
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• pp.179-187
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• 1988

This study was conducted to investigate the effects of epinephrine and norepinephrine on basal gastric acid secretion and plasma gastrin and secretin concentration in the conscious rat. One hundred and eighty-four albino rats with gastric cannula were used after 18 hours or more of fast, with water ad libitum. In a restraint cage for collection of gastric juice, physiological saline (0.9% NaCl) was continuously infused into the jugular vein through a catheter for one hour at a rate of 1 ml/hr (control period). Immediately after the control period, epinephrine (1, 2, 4, 8 and $16{\mu}g/ml/hr)$, norepinephrine (1, 2, 4, 8 and $16{\mu}g/ml/hr)$ or physiological saline (1 ml/hr) was infused for another one hour. Gastric juice was collected at one hour interval for two hours infusion period. Adrenergic antagonists, phentolamine and propranolol were injected into the jugular vein 5 min prior to the infusion of epinephrine or norepinephrine at a dose of 0.2 mg/0.1 ml. Blood was sampled from the jugular vein for the radioimmunoassay of plasma gastrin and secretin after the collection of gastric juice. The results were as follows: 1) Both epinephrine and norephinephrine significantly increased gastric acid output in a dosedependent manner. 2) The effects of epinephrine and norepinephrine on the gastric acid secretion were antagonized by the pretreatment with phentolamine and propranolol. 3) Plasma gastrin and secretin concentrations were not significantly affected by the intravenous infusion of epinephrine and norepinephrine. It can be inferred from the above results that epinephrine and norepinephrine facilitate gastric acid secretion in conscious rats and the mechanism of which is attributed to ${\alpha}\;and\;{\beta}$ adrenergic receptors rather than gastrin and secretin.

• 대한약리학회지
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• 제17권1호
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• pp.27-32
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• 1981

It has been known that ethanol stimulates the secretion of gastric acid regardless of its route of administration. Recently, however, some studies have challenged this view and claimed that ethanol inhibits the gastric acid secretion. This study was undertaken to investigate the effects of ethanol on the gastric acid secretion in anesthetized rat in respect to the route of administration and the concentration of alcohol. Normal saline (pH adjusted to 6.0) was used as standard perfusion solution and ethanol was mixed as 0.8, 1.7, 5, 10 and 20%. Four ml of perfusion fluid was given into stomach via gastric tube and drained from duodenal tube every 5 min. Acid secretion was measured by back titration to pH 6.0 with N/20 NaOH and expressed as ${\mu}Eq/5$ min. Low concentration of ethanol up to 1.7% in perfusion solution caused little changes in acid secretion, but moderate concentration such as perfusion of 5% or 10% ethanol solution inhibited both the basal and histamine-induced gastric secretion. Moreover, loss of perfused acid was seen by 20% ethanol, which means back diffusion of hydrogen ions into the gastric mucosa. However, intravenous administration of ethanol, maintained at the level of 0.1% alcohol in blood, caused significant stimulation of gastric acid. We, therefore, conclude that in anesthetized rat ethanol has dual effects on acid secretion, i.e., inhibiting and enhancing by oral and intravenous administration, respectively, but further investigation is necessary to clarify these effects.

• Biomolecules & Therapeutics
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• 제8권4호
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• pp.318-324
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• 2000

We have examined inhibitory erects on gasritis using omeprazole-cholestyramine resinate, which has been developed to increase the stability of omeprazole, the well-known proton pump inhibitor, in an acidic condition. To test the pharmacological action of this, we investigated the effect of omeprazole-cholestyramine resinate on indomethacin-induced gastritis in rats. Omeprazole was used as a reference drug. Orally administered omeprazole-cholestyramine resinate inhibited the indomethacin-induced gastritis in a dose-dependent manner. The inhibitory effect of omeprazole-cholestyramine resinate on the gastritis was similar to that of reference drug. In addition, rectal adminstration of the omeprazole-cholestyramine resinate inhibited the indomethacin-induced gastritis in a dose-dependent manner. The inhibitory effect of omeprazole-cholestyramine resinate was equipotent to reference drug. The basal gastric acid secretion was decreased when it was administered either orally or rectally. This inhibition of omfprazole-cholestyramine resinate was similar to that of omeprazole. These data suggest that omeprazole-cholestyramine resinate inhibit the gastritis in rats, and are comparable to omeprazole available in market.

• Biomolecules & Therapeutics
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• 제10권3호
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• pp.142-151
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• 2002

The present study was attempted to investigate the effect of apamin on catecholamine (CA) secretion evoked by ACh, high $K^+$, DMPP, McN-A-343, cyclopiazonic acid and Bay-K-8644 from the isolated perfused rat adrenal gland and to establish the mechanism of its action. The perfusion of apamin (1 nM) into an adrenal vein for 20 min produced greatly potentiation in CA secretion evoked by ACh (5.32 $ imes$ $10^{-3}$ M), high $K^+$, (5.6 $ imes$ $10^{-2}$), DMPP ($10^{-4}$ M for 2 min), McN-A-343 ($10^{-4}$ M for 2 min), cyclopiazonic acid ($10^{-5}$ M for 4 min) and Bay-K-8644 ($10^{-5}$ M for 4 min). However, apamin itself did fail to affect basal catecholamine output. Furthermore, in adrenal glands preloaded with apamin (1 nM) under the presence of glibenclamide ($10^{-6}$ M), an antidiabetic sulfonylurea that has been shown to be a specific blocker of ATP-regulated potassium channels (for 20 min), CA secretion evoked by DMPP and McN-A-343 was not affected. However, the perfusion of high concentration of apamin (100 nM) into an adrenal vein for 20 min rather inhibited significantly CA secretory responses evoked by ACh, high $K^+$, DMPP, McN-A-343, cyclopiazonic acid and Bay-K-8644. Taken together, these results suggest that the low concentration of apamin causes greatly the enhancement of CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as by membrane depolarization. These findings suggests that apamin-sensitive SK ($Ca^{2+}$) channels located in rat adrenal medullary chromaffin cells may play an inhibitory role in the release of catecholamines mediated by stimulation of cholinergic nicotinic and muscarinic receptors as well as membrane depolarization. However, it is thought that high concentration of apamin cause the inhibitory responses in catecholamine secretion evoked by stimulation of cholinergic receptors as well as by membrane depolarization from the rat adrenal gland without relevance with the SK channel blockade.

• Biomolecules & Therapeutics
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• 제5권3호
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• pp.228-232
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• 1997

AU-164 was synthesized as a reversible gastric $H^+/K^+$ ATPase inhibitor, and its effects were tested in various systems. AU-164 inhibited rabbit gastric $H^+/K^+$ ATPase with an $IC_{50}$/ of 9 $\mu$M. On the other hand, AU-164 was a weak inhibitor for dog kidney $Na^+/K^+$ ATPasc, indicating the selectivity for gastric $H^+/K^+$ ATPase. The reversible property of the AU-164-induced inhibition of $H^+/K^+$ ATPase was confirmed by filtering the inhibition mixture through Sephadex G-25M column. In vivo basal acid secretion was also inhibited by AU-164 under the pylorus ligation of Sprague-Dawley rats. In addition, AU-164 protected dose dependently gastric lesion induced by ethanol in rats. The $ED_{50}$ value of 62 mg/kg p.o was estimated. These results suggest that AU-164 is a potent, selective and reversible gastric $H^+/K^+$ ATPase inhibitor, and that AU-164 has a potential use for the clinical therapeutics of peptic ulcer disease.