• Korean Journal of Veterinary Research
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• v.35 no.1
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• pp.45-54
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• 1995

Pancreatic endocrine cells containing glucagon, insulin, somatostatin and pancreatic polypeptide were identified in the pancreas of the Korean native goat by using immunohistochemical method. Glucagon immunoreative cells were oval or fusiform in shape and located at the periphery of the pancreatic islets. Insulin immunoreactive cells were round or oval in shape and occupied throughout the pancreatic islets except the small area of the periphery. Somatostatin immunoreative cells were oval and elliptical, and mainly located at the periphery of the pancreatic islets. Some of these cells had a cytoplasmic process. Pancreatic polypeptide immunoreactive cells were elliptical or polyhedral and located at the periphery of the pancratic islets where two or more cells formed a cell cluster. The distribution rates of glucagon, insulin, somatostatin and pancreatic polypeptide immunoreactive cells were 24.4%, 44.3%, 13.2% and 18.1% respectively.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.3
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• pp.219-225
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• 2022

Glucagon like peptide-1 (GLP-1) released from enteroendocine L-cells in the intestine has incretin effects due to its ability to amplify glucose-dependent insulin secretion. Promotion of an endogenous release of GLP-1 is one of therapeutic targets for type 2 diabetes mellitus. Although the secretion of GLP-1 in response to nutrient or neural stimuli can be triggered by cytosolic Ca²⁺ elevation, the stimulus-secretion pathway is not completely understood yet. Therefore, the aim of this study was to investigate the role of reverse Na⁺/Ca²⁺ exchanger (rNCX) in Ca²⁺ entry induced by muscarinic stimulation in NCI-H716 cells, a human enteroendocrine GLP-1 secreting cell line. Intracellular Ca²⁺ was repetitively oscillated by the perfusion of carbamylcholine (CCh), a muscarinic agonist. The oscillation of cytosolic Ca²⁺ was ceased by substituting extracellular Na⁺ with Li⁺ or NMG⁺. KB-R7943, a specific rNCX blocker, completely diminished CCh-induced cytosolic Ca²⁺ oscillation. Type 1 Na⁺/Ca²⁺ exchanger (NCX₁) proteins were expressed in NCI-H716 cells. These results suggest that rNCX might play a crucial role in Ca²⁺ entry induced by cholinergic stimulation in NCI-H716 cells, a GLP-1 secreting cell line.

• 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.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.1
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• pp.31-38
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• 2024

As in type 1 diabetes, the loss of pancreatic β-cells leads to insulin deficiency and the subsequent development of hyperglycemia. Exercise has been proposed as a viable remedy for hyperglycemia. Lithium, which has been used as a treatment for bipolar disorder, has also been shown to improve glucose homeostasis under the conditions of obesity and type 2 diabetes by enhancing the effects of exercise on the skeletal muscles. In this study, we demonstrated that unlike in obesity and type 2 diabetic conditions, under the condition of insulin-deficient type 1 diabetes, lithium administration attenuated pancreatic a-cell mass without altering insulin-secreting β-cell mass, implying a selective impact on glucagon production. Additionally, we also documented that lithium downregulated the hepatic gluconeogenic program by decreasing G6Pase protein levels and upregulating AMPK activity. These findings suggest that lithium's effect on glucose metabolism in type 1 diabetes is mediated through a different mechanism than those associated with exercise-induced metabolic changes in the muscle. Therefore, our research presents the novel therapeutic potential of lithium in the treatment of type 1 diabetes, which can be utilized along with insulin and independently of exercise.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.6
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• pp.885-891
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• 2013

The abilities of instant gruel manufactured with colored barley and oats to improve diabetic conditions were investigated using diabetes-induced mice and rats. Mice or rats were divided into a diabetic control group and one experimental group (seven animals per group). The control groups were fed without instant gruel and experimental groups were fed basal diets supplemented with 10% instant gruel for 8 weeks. The streptozotocin (STZ)-induced diabetic rats experimental group showed a significant decrease in food intake compared to the control group. Both Type II diabetic mice and STZ-induced diabetic rats experimental groups showed higher increases in body weight than the control groups. The blood glucose levels of the experimental groups ($352{\pm}12.2$ mg/dL in Type II diabetic mice; $296.4{\pm}13.2$ mg/dL in STZ-induced diabetic rats) were lower than the untreated control groups ($426.0{\pm}15.4$ mg/dL in Type II diabetic mice; $514.0{\pm}17.6$ mg/dL in STZ-induced diabetic rats). The serum insulin levels of Type II diabetic mice increased by 38.3% in the experimental group ($12.8{\pm}1.1$ ng/mL) compared to the control group ($7.9{\pm}0.5$ ng/mL). The immunohistochemical density of insulin-secreting cells and glucagon-like peptide-1 (GLP-1)-secreting cells in the pancreas were significantly higher in the experimental groups than the control groups for Type II diabetic mice and STZ-induced diabetic rats. Therefore, we conclude that instant gruel manufactured with colored barley and oats stimulates the secretion of insulin and decreases blood sugar by activating insulin-secreting cells in the pancreatic islets of diabetic animals.