• Korean Journal of Veterinary Research
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• v.33 no.4
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• pp.573-577
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• 1993

The pancreatic endocrine cells, glucagon and somatostation, of the Korean tree squirrel. Sciurus vulgais corea, were investigation by means of light and electron microscopic immunohistochemistry using the PAP and protein A-gold techniques. Glucagon-immunoreactive cells were distributed the periphery and occasinonaly central region of the pancreatic islets. Also, isolated cell was found between the pancreatic ancinar cells. The glucagon cells contraine granules with a diameter of 240~320nm and the electron dense core usually surrounded by a halo of less dense granular material. The core of granule was labelled strongly with gold particles. Somatostatin-immunoreactive cells were weakly stained in scattered along the peripheral pancreatic islets and were distributed as singly or small groups with in the pancreatic acinar cells. The somatostatin cells were spherical with a diameter of 250~275nm, moderately electron opaque (Gold particles were mostly demonstrated on the entire granule.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.239-245
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• 1998

The distributions and relative frequencies of insulin-, glucagon-, and somatostatin-immunoreactive cells in the pancreas of the duck(Anas platyrhynchos platyrhyncos, Linne) were investigated immunohistochemically on 23 days of incubation, at hatching, 1 week, 2 weeks, 3 weeks, 5 weeks, 6 weeks, 7 weeks, 9 weeks, 10 weeks, and 32 weeks after hatching. In the duck pancreas on 23 days of incubation and at hatching, mammalian type islets(mixed type) were only observed, thereafter three type's islets(mamalian, A and B type's islets) were identified. Insulin-immunoreactive cells were detected in central region of the islets, while glucagon- and somatostatin-immunoreactive cells were detected in marginal region of light(B type) or mammalian type islets, and in central region of dark islets(A type). Insulin-, and somatostatin-immunoreactive cells were also detected in the exocrine regions. In this region the insulin-immunoreactive cells were detected from 23 days of incubation to 6 weeks, however not detected after 7 weeks. At hatching the relative numbers of somatostatin-immunoreactive cells were more frequent than those of other groups, and then decreased with ages.

• Korean Journal of Veterinary Research
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• v.28 no.2
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• pp.251-259
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• 1988

Regional distribution and relative frequency of endocrine cells in ten portions of the gastrointestinal tract of the Korean native cattle were observed by immunocytochemical methods using specific antisera against chromogranin, serotonin, somatostatin, glucagon, bovine pancreatic polypeptide(BPP), motilin, gastric inhibitory polypeptide(GIP), neurotensin, secretin, gastrin and substance P. The results observed are summarized as follows: In the abomasum, chromogranin-, serotonin-, somatostatin-, motilin-, glucagon-, gastrin-, and substance P-immunoreactive cells were found. Chromogranin-and serotonin-immunoreactive cells were more numerous in the fundic region than pyloric region. Somatostatin- and gastrinimmunoreactive cells were numerous in the pyloric region than in the fundic region. In the small intestine, chromogranin-, serotonin-, somatostatin-, glucagon-, BPP-, motilin-, gastrin-, GIP-, neurotensin-, secretin-, and substance P-immunoreactive cells were detected. Chromogranin-, somatostatin-, GIP- and secretin-immunoreactive cells were most numerous in the duodenum, while BPP-, motilin-, glucagon-, neurotensin- and substance P-immunoreactive cells were rarely seen in the small intestine. In the large intestine, chromogranin-, serotonin- and BPP-immunoreactive cells were widely distributed and most numerous in the rectum. Somatostatin-, glucagon- and substance P-immunoreactive cells were rarely seen in the large intestine.

• Korean Journal of Veterinary Research
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• v.35 no.1
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• pp.55-65
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• 1995

Ultrastructures of pancreatic endocrine cells containing glucagon, insulin, somatosratin and pancreatic polypeptide were studied in the pancreas of the Korean native goat by immunohistochemical and elecron microscopy. Glucagon immunoreatctive cells were round or fusiform in shape and contained secretory granules of 200-260 nm in diameter. The secretory granules were high in electron density and had a halo between the limiting membrane and the central granule core. Insulin immunoreactive cells were round or oval in shape, and contained various sizes of secretory granules from 135 to 300 nm in diameter. The secretory granules were low or moderate electron density and had a variform halo. Somatostatin immunoreactive cells were elliptical or fusiform shape with cytoplasmic processes. They contained the secretory granules of 140-320 nm with moderate electron densities. Pancreatic polypeptide immunoreactive cells were elliptical or fusiform and contained small secretory granules with high electron densities. The secretory granules were 120-230 nm in diameter and the least in number.

• Annals of Pediatric Endocrinology and Metabolism
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• v.22 no.1
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• pp.15-26
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• 2017

The prevalence of type 2 diabetes (T2D) is increasing worldwide. Patients with T2D suffer from various diabetes-related complications. Since there are many patients with T2D that cannot be controlled by previously developed drugs, it has been necessary to develop new drugs, one of which is a glucagon-like peptide-1 (GLP-1) based therapy. GLP-1 has been shown to ameliorate diabetes-related conditions by augmenting pancreatic ${\beta}-cell$ insulin secretion and having the low risk of causing hypoglycemia. Because of a very short half-life of GLP-1, many researches have been focused on the development of GLP-1 receptor (GLP-1R) agonists with long half-lives such as exenatide and dulaglutide. Now GLP-1R agonists have a variety of dosing-cycle forms to meet the needs of various patients. In this article, we review the physiological features of GLP-1, the effects of GLP-1 on T2D, the features of several GLP-1R agonists, and the therapeutic effect on T2D.

• Applied Microscopy
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• v.25 no.1
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• pp.122-129
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• 1995

Pancreatic endocrine cells of the native Korean goat were investigated immunocytochemically at electron microscopic level. All glucagon-, insulin-, somatostatin- and pancreatic polypeptide(PP)-immunoreactive cells were showed chromogranin(CG) immunoreactivity in the secretory granules of each cells. In addition, bovine pancreatic polypeptide immunoreactivity was found to be colocalized in the secretory granules of the glucagon and insulin cells. These observations support that chromogranin is available as the marker of pancreatic endocrine cells on the native Korean goat and BPP colocalized in the secretory granules of glucagon and insulin cells.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.1
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• pp.13-16
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• 2000

Simple procedures have been devised for purifying recombinant human interleukin-2 (hIL-2), which was expressed in Escberichia coli using sequences of glucagon molecules and enterokinase cleavage site as an N-terminus fusion partner. The insoluble aggregates of recombinant fusion protein produced in E. coli cytoplasm were easily dissolved by simple alkaline pH shift $(8\rightarrow12\rightarrow8)$. Following enterokinase cleavage, the recombinant hIL-2 was finally purified by one-step reversed-phase HPLC with high purity. The ease and high efficiency of this simple purification process seem to mainly result from the role of used glucagon fusion partner, which could be applied to the production of other therapeutically important proteins.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.1-8
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• 1997

The relative frequency and distribution of occurrence of immunoreactive cells in the proventriculus, diverticulum, cardia, fundus and pylorus of the stomach of pigs were investigated by PAP method using specific antisera against BCG, Gas/CCK, 5-HT, somatostatin, glucagon, BPP, motilin and insulin. In the diverticulum and cardia, BCG-, 5-HT-, somatostatin- and glucagon-immunoreactive cells were detected. In the fundus, BCG-, 5-HT- and somatostatin-immunoreactive cells were also found. In the pylorus, BCG-, Gas/CCK-, 5-HT-, somatostatin- and glucagon-immunoreactive cells were observed. However, no BPP-, motilin- and insulin-immunoreactive cells were found in the stomach epithelium of the pigs. These results showed that the occurrence of the endocrine cells confirmed in the diverticulum as the cardia and suggest that the function of diverticulum may be similar to that of cardia in the pigs.

• Journal of Integrative Natural Science
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• v.10 no.3
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• pp.125-130
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• 2017

Glucagon like pepide-2, one of the GLPs, is involved in various metabolic functions in the gastrointestinal tract. It plays a major role in the regulation of mucosal epithelium and the intestinal crypt cell proliferation. Because of their therapeutic importance towards the diseases in the gastrointestinal tract, it becomes necessary to study their interaction with its receptor, GLP-2R. In this study, we have developed protein-protein docking complexes of GLP-2 - GLP-2 receptor. Homology models of GLP-2 are developed, and a reliable model out of the predicted models was selected after model validation. The model was bound with the receptor, to study the important interactions of the complex. This study could be useful in developing novel and potent drugs for the diseases related with GLP-2.

• Environmental Analysis Health and Toxicology
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• v.21 no.3 s.54
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• pp.245-253
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• 2006

We reported previously that glucagon decreased alpha- and pi-class glutathione S-transferases (GSTs) and microsomal epoxide hydrolase (mEN) protein levels in primary cultured rat hepatocytes. The present study examines the effects of Protein kinase A (PKA) inhibitor, KT5720, on the glucagon-mediated decrease in expression of GSTs and mEN. To assess cell viability. lactate dehydrogenase release and MTT activity were examined in hepatocytes treated KT5720. Cell viability was significantly decreased in a concentration dependent manner after incubation with KT5720 at the concentrations of 1 $\mu$M or above for 24 h, which was inhibited by the cytochrome P450 inhibitor SKF-525A. In contrast, another PKA inhibitor H89 (up to 25 $\mu$M) was not toxic to hepatocytes. The glucagon-mediated decrease in expression of alpha- and pi-class GSTs and mEH was completely inhibited by 25 $\mu$M H89 and attenuated by 0.1 $\mu$M KT5720. This study demonstrates that KT5720 may cause cytotoxicity in rat hepatocytes through cytochrome P450-dependent bioactivation. The present study implicates PKA in mediating the inhibitory effect of glucagon on expression of alpha- and pi- class GSTs and mEH.