• The Korean Journal of Physiology and Pharmacology
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• 제2권2호
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• pp.185-192
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• 1998

A role of endogenous somatostatin in pancreatic exocrine secretion induced by intrapancreatic cholinergic activation was studied in the isolated rat pancreas perfused with modified Krebs-Henseleit solution. Intrapancreatic neurons were activated by electrical field stimulation (EFS: 15 V, 2 msec and 8 Hz). Pancreatic exocrine secretion, including volume flow and amylase output, and release of somatostatin from the pancreas were respectively determined. Somatostatin cells in the islet were stained with an immunoperoxidase method. EFS significantly increased pancreatic volume flow and amylase output, which were reduced by atropine by 59% and 78%, respectively. Intraarterial infusion of either pertussis toxin or a somatostatin antagonist resulted in a further increase in the EFS-evoked pancreatic secretion. EFS also further elevated exocrine secretion in the pancreas treated with cysteamine, which was completely restored by intraarterial infusion of somatostatin. EFS significantly increased not only the number of immunoreactive somatostatin cells in the islet but also the concentration of immunoreactive somatostatin in portal effluent. It is concluded from the above results that intrapancreatic cholinergic activation elevates pancreatic exocrine secretion as well as release of endogenous somatostatin. Endogenous somatostatin exerts an inhibitory influence on exocrine secretion induced by intrapancreatic cholinergic activation via the islet-acinar portal system in the isolated pancreas of the rat.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.187-188
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• 1989

• The Korean Journal of Physiology and Pharmacology
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• 제1권1호
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• pp.83-90
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• 1997

Aim of this study was to investigate if pancreatic polypeptide (PP) reduced the insulin action via the intra-pancreatic cholinergic nerves in the isolated rat pancreas. The pancreas was isolated from rats and perfused with intra-arterial infusion of modified Krebs-Henseleit solution containing 2.5 mM glucose at a flow rate of 1.2 ml/min. Simultaneous intra-arterial infusion of insulin (100 nM) resulted inpotentiation of the pancreatic flow rate and amylase output which were stimulated by cholecystokinin (CCK, 14 pM). These potentiating actions of insulin on the CCK -stimulated pancreatic exocrine secretion were completely abolished by administration of rat PP. Vesamicol, a potent inhibitor of vesicular acetylcholine storage, and tetrodotoxin (TTX) also significantly reduced the combined actions of insulin and CCK. Administration of carbamylcholine, an acetylcholine agonist, completely restored the vesamicol- or TTX-induced inhibition of the potentiation between insulin and CCK. Also rat PP failed to attenuate the restoring effect of carbamylcholine. Electrical field stimulation (15-30 V, 2 msec and 8 Hz) resulted in a significant increase in the pancreatic flow rate and amylase output in voltage-dependent manner. Effects of electrical field stimulation were augmented by endogenous insulin. Rat PP also suppressed the pancreatic exocrine secretion stimulated by electrical field stimulation. These observations strongly suggest that PP inhibits the potentiating actions of insulin on CCK -stimulated pancreatic exocrine secretion by suppression of the intra-pancreatic cholinergic activity in the isolated rat pancreas.

• 한국가금학회지
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• 제16권4호
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• pp.219-232
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• 1989

본 연구는 닭에 있어서 사료성분에 대한 췌장소화효소(amylase. trypsinogen 및 chymotrypsinogen) 분비기구에 대해서 검토했다. 먼저, 췌효소분비의 단기응답실험에 유용한 새로운 췌액채취법을 개발했다. 이 방법을 이용해서 아미노산 및 glucose를 날개정맥으로 투여한 결과 phenylalanine만이 trypsinogen 및 Chymotrypsinogen이 증가되었지만 그 외의 아미노산 및 glucose에 의해서는 분비증가 효과가 없었다. Cholecystokinin(CCK)투여 에 의해 췌효소분필는 즉각적으로 높은 분비반응을 보였으며, 이 반응은 또한 농도의존성을 나타냈다. CCK투여는 chymotrypsinogen의 쪽이 amylase 및 trypsinogen보다 높은 비율로 분비되는 선택적인 분비반응을 나타냈다. 아미노산과 CCK을 공동투여하면 첨가한 아미노산의 종류에 따라 췌효소분비반응은 여러 가지 형태로 증가되었지만 glucose와의 공동투여에서는 CCK 단독투여와 비교해서 차가 없었다. Valine과 arginine을 여러 가지 농도로 CCK와 공동 투여한 결과, valnine에서는 0.5mM일때, arginin에서는 5mM일때 가장 높은 분비반응을 보였다. 위의 결과로부터 아미노산의 조합에 의한 췌효소분비반응에 대해서 검토했다. 즉, 아미노산 mixture, threonine＋phenylalanine＋isoleucine, Threonine＋phenylalanine, threonine＋isoleucine 및 phenylalanine＋isoleucine과 CCK를 공동투여 했다. 각 물질을 투여한 후 50분간 분비한 효소를 비교하면, threonine＋phenylalanine에 의한 췌효소분비반응은 아미노산 mixture에 의한 분비반응과 동일하게 높은 반응을 보였다. 이상의 결과로부터 닭에 있어서 췌장소화효소분비는 CCK와 아미노산의 사이에 협동작용이 있으며, 그 협동작용은 아미노산의 종류에 따라 선택적인 분비반응을 함으로써 장내소화가 진행된다고 본다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권5호
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• pp.654-660
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• 2013

Three Korean native steers ($779{\pm}24$ kg) fitted with duodenal cannulas were used in a $3{\times}3$ Latin square design to investigate the influence of oral administration of soluble proteins, intact casein (IC) and acid hydrolyzed casein (AHC), on gastro-intestinal hormone (GIH) secretion in the blood and pancreatic ${\alpha}$-amylase activity in the duodenum. Oral treatment consisted of a basic diet (control), IC (C+100% protein), or AHC (C+80% amino acid, 20% peptide) for 21 d. Blood and duodenum samples were collected for measurement of serum GI hormones, and pancreatic ${\alpha}$-amylase activity was determined at 900, 1030, 1330, 1630, and 1930 h after feeding on d 21 of treatment. The levels of serum cholecystokinin (CCK) and secretin in the IC treatment group were higher compared to the other treatment groups (p<0.05). In addition to the changes in CCK and secretin levels upon IC treatment, the pancreatic ${\alpha}$-amylase activity in the duodenum was higher in the IC group compared to the control diet group (p<0.05). The response of serum ghrelin to IC and AHC treatment was in accordance with the response of serum secretin. The level of peptide fragments flowing in the duodenum was higher in the IC treatment group than the other treatment groups (p<0.05). In conclusion, this study demonstrated that an increase in duodenal CCK and secretin upon IC oral administration increased pancreatic ${\alpha}$-amylase secretion. In addition, ghrelin may be associated with GI hormone secretion in Korean native steers.

• Journal of Animal Science and Technology
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• 제56권2호
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• pp.6.1-6.4
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• 2014

The aims of study were to investigate the effects of intraperitoneal (i.p.) infusion of ghrelin on pancreatic ${\alpha}$-amylase outputs and the responses of pancreatic proteins to ghrelin that may relate to the pancreatic exocrine. Six male Sprague-Dawley rats (300 g) were randomly divided into two groups, a control group (C, n = 3) and a treatment group (T, $10.0{\mu}g/kg$ BW, n = 3). Blood samples were collected from rat caudal vein once time after one hour injection. The concentrations of plasma ghrelin, cholecystokinin (CCK) and alfa-amylase activity were evaluated by enzyme immunoassay (EIA) kit. Two-dimensional gel electrophoresis (2-DE) analysis was conducted to separate the proteins in pancreas tissue. Results showed that the i.p. infusion of ghrelin at doses of $10.0{\mu}g/kg$ body weight (BW) increased the plasma ghrelin concentrations (p = 0.07) and elevated the plasma CCK level significantly (p < 0.05). Although there was no statistically significant, the ${\alpha}$-amylase activity tended to increase. The proteomics analysis indicated that some pancreatic proteins with various functions were up- or down-regulated compared with control group. In conclusion, ghrelin may have role in the pancreatic exocrine, but the signaling pathway was still not clear. Therefore, much more functional studies focus on these found proteins are needed in the near future.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.657-663
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• 1998

The enzyme responsible for the synthesis of nitric oxide (NO) from L-arginine in mammalian tissues is known as nitric oxide synthase (NOS) (EC.1.14.13.39). In the present study, the role of NO in the regulation of exocrine secretion was investigated in rat pancreatic acinar cells. Treatment of rat pancreatic acinar cells with cholecystokinin-octapeptide (CCK-OP) resulted in an increase in the arginine conversion to citrulline, the amount of $NO_X$, the release of amylase, and the level of CGMP. Especially, CCK-OP-stimulated increase of arginine to citrulline transformation, the amount of $NO_X$, and CGMP level were completely counteracted by the inhibitor of NOS, NG-monomethyl-L-arginine (MMA), by contrast, that of amylase release was partially reduced. Furthermore, MMA-induced decrease of NOS activity and amylase release showed dose-dependent pattern. The data on the time course of CCK-OP-induced citrulline formation and CGMP rise indicate that NOS and guanylate cyclase were activated by treatment of CCK-OP. However, the mechanism of agonist-stimulated guanylate cyclase activation in acinar cells remains unknown. Therefore, activation of NOS is one of the early events in receptor-mediated cascade of reactions in pancreatic acinar cells and NO, not completely, but partially mediate pancreatic enzyme exocrine secretion.

• Asian-Australasian Journal of Animal Sciences
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• 제13권8호
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• pp.1050-1053
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• 2000

Biological evaluation of residual malathion after 168 hrs of single dipping exposure of White Leghorn hens to different concentrations (0, 0.5, 1.0 and 1.5%) of pesticides was investigated. Thirty-two male albino rats divided into four groups of eight each were kept on 20% isoproteinous diet prepared from the meat of these malathion dipped hens. After 30 days feeding trial, the rats were killed by decapitation. No significant change was found in erythrocytes. However, the triglyceride concentration in brain tissue was increased significantly (p<0.05) when dose level of pesticide was 1% in dipping solution. Similarly, malathion exposed poultry meat failed in altering any significant change in the pancreatic amylase and lipase activities of rats. This study concludes the virtual absence of toxic accumulation of pesticide in the meat of birds after 168 hrs of exposure in usual concentration range upto 1.5%.

• International Journal of Oral Biology
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• 제31권4호
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• pp.127-133
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• 2006

[ $H_2O_2$ ], a member of reactive oxygen species (ROS), is known to be involved in the mediation of physiological functions in a variety of cell types. However, little has been known about the physiological role of $H_2O_2$ in exocrine cells. Therefore, in the present study, the effect of $H_2O_2$ on cholecystokinin (CCK)-evoked $Ca^{2+}$ mobilization and amylase release was investigated in rat pancreatic acinar cells. Stimulation of the acinar cells with sulfated octapeptide form of CCK (CCK-8S) induced biphasic increase in amylase release. Addition of $30\;{\mu}M\;H_2O_2$ enhanced amylase release caused by 10 pM CCK-8S, but inhibited the amylase release induced by CCK-8S at concentrations higher than 100 pM. An ROS scavenger, $10\;{\mu}M$ Mn(III)tetrakis(4-benzoic acid)porphyrin chloride, increased amylase release caused by CCK-8S at concentrations higher than 100 pM, although lower concentrations of CCK-8S-induced amylase release was not affected. To examine whether the effect of $H_2O_2$ on CCK-8S-induced amylase release was exerted via modulation of intracellular $Ca^{2+}$ signaling, we measured the changes in intracellular $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ in fura-2 loaded acinar cells. Although $30\;{\mu}M\;H_2O_2$ did not induce any increase in $[Ca^{2+}]_i$ by itself, it increased the frequency and amplitude of $[Ca^{2+}]_i$ oscillations caused by 10 pM CCK-8S. However, $30\;{\mu}M\;H_2O_2$ had little effect on 1 nM CCK-8S-induced increase in $[Ca^{2+}]_i$. ROS scavenger, 1 mM N-acetylcysteine, did not affect $[Ca^{2+}]_i$ changes induced by 10 pM or 1 nM CCK-8S. Therefore, it was concluded that $30\;{\mu}M\;H_2O_2$ enhanced low concentration of CCK-8S-induced amylase release probably by increasing $[Ca^{2+}]_i$ oscillations while it inhibited high concentration of CCK-8S-induced amylase release.

• Asian-Australasian Journal of Animal Sciences
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• 제19권12호
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• pp.1749-1754
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• 2006

Two slaughter experiments were conducted to determine the effects of rumen escape starch, by altering dietary starch concentration and corn particle size, on ${\alpha}$-amylase activity in the pancreas and the small intestinal digesta of lambs. In experiment 1, 18 wether lambs (28.5${\pm}$1.6 kg) were fed low, medium or high starch diets for 35 d and slaughtered. Dietary starch concentrations linearly increased rumen escape starch (p<0.05). Pancreatic ${\alpha}$-amylase activity was lower (p<0.05) in lambs fed the low starch diet. When expressed per gram of digesta, ${\alpha}$-amylase activity was lower in lambs fed the low starch diet. However, expressed as total activity, ${\alpha}$-amylase in the digesta was greater in lambs fed the medium starch diet. In experiment 2, 12 wether lambs (23.5${\pm}$0.3 kg) were fed diets with finely cracked corn, coarsely cracked corn and whole corn. These dietary treatments continued for 35 d before tissue collection. Rumen escape starch increased with increasing corn particle size (p<0.05). ${\alpha}$-amylase activity in the pancreas and the small intestinal digesta was significantly greater (p<0.05) in lambs fed the coarsely cracked corn. These data suggest that increasing rumen escape starch results in a quadratic increase in total ${\alpha}$-amylase activity in the pancreas and the small intestinal digesta. Maximum ${\alpha}$-amylase activity is reached when rumen escape starch is about 100-120 g/d in 25-30 kg lambs.