• Title/Summary/Keyword: rat islets

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STRUCTURE, SYNTHESIS, AND BIOLOGICAL FUNCTION OF NATURAL PRODUCTS IN DEER ANTLER AND THEIR DERIVATIVES

  • Kim, So-Yeon;Jhon, Gil-Ja;Lee, Yoon-Jin;Cho, So-Hye;Han, So-Yeop
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1998.11a
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    • pp.126-126
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    • 1998
  • Studies on natural products are of great interest, due to the limits in development of synthesized medicine and its side effects. Deer antler is the most popular cure-all type drug among Asian folk medicines. In this study, we newly isolated the biologically active components from chloroform extract and 70% ethanol extract of deer antler, and analyzed their structures. First, the structure of monoacetyldiglyceride in deer antler was identified. To investigate the structure-activity relationship of monoacetyldiglycerides, we synthesized diverse substituted glycerides from glycerol, and confirmed their structures by spectroscopic methods. Among seven structurally-interesting compounds tested in this study, compound 1,2,3,5, and 6 showed activity toward [Ca$\^$2+/]$\_$i/ increase in fura-2 loaded rat pancreatic acinar cells. Second, 70% ethanol extract of deer antler stimulated insulin release from rat pancreatic islets. We found the most effective fraction was CN-Es-8 in 70% ethanol extract, and it increased intracellular Ca$\^$2+/ concentration in pancreatic ${\beta}$-cell.

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Effect of Garlic Diets on the Changes of Serum Cholesterol Glucose Level and Coagulation Time in Rats (마늘첨가식이(添加食餌)가 흰쥐의 혈청(血淸) 콜레스테롤, 글루코오스의 함량(含量) 및 혈액응고시간(血液凝固時間)에 미치는 영향(影響))

  • Kim, Song-Jen
    • Journal of the Korean Applied Science and Technology
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    • v.1 no.1
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    • pp.37-47
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    • 1984
  • Effects of garlic on hypocholesterolemia, anticoagulation and hypoglycemia were studied in the present experiments using male rats. The results were summarized as follows. 1. The supplementation of $2{\sim}4%$ garlic to 2% cholesterol diets did not affect food intake and weight gain in male rats. 2. Rat's groups fed the diets supplemented with $2{\sim}3%$ garlic (C.D.E.F) to 2% cholesterol diet (B) decreased serum total cholesterol levels by $16{\sim}32%$, triglyceride levels by $18.6{\sim}26.8%$ and ${\beta}/{\alpha}-lipoportein$ rations by $42{\sim}58%$, but increased HDL-cholesterol levels by $29{\sim}65%$ as compared to B group, and so the author assumes that garlic supplementation exerts hypocholesterolemic effect on cholesterol - fed rats because of the increase of HDL and HDL - cholesterol levels. 3. Rat's groups fed the diets supplemented with $2{\sim}4%$ garlic (C.D.E.F) to 2% cholesterol plus 0.25% bile salt diet (B) increased whole blood coagulation times, prothrombin times and fibrinolytic activities, but decreased plasma fibrinogen levels as compared to B group, and so the author assumes that garlic supplementation exerts anticoagulative effect because of the inhibition of fibrinogen synthesis in male rat's liver. 4. Rat's groups fed the diets supplemented with $2{\sim}4%$ garlic (B.C.D.E) to standard diet (A) decreased serum glucose levels by $1{\sim}24%$, but increased serum insulin concentrations by $0.5{\sim}3.0$ times as compared to A group, and so the author assumes that garlic supplementation exerts hypoglycemic effect because of the increase of serum insulin levels by stimulation pancreatic secretion of insulin from ${\beta}-cells$ in the islets of Langerhans.

Silymarin attenuates escitalopram (cipralex) induced pancreatic injury in adult male albino rats: a biochemical, histological, and immunohistochemical approach

  • Rasha Mamdouh Salama;Sara Gamal Tayel
    • Anatomy and Cell Biology
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    • v.56 no.1
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    • pp.122-136
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    • 2023
  • Depression is a prevalent global problem since ages, predominately treated with SSRI. Cipralex, is an antidepressant of the SSRIs class used as a remedy for mood, depression and anxiety. Silymarin (SIL), a natural free radical scavenging, has an antioxidant and anti-inflammatory properties. This hypothesis evaluates, for the first time, the role of cipralex on the structure of the endocrine and exocrine components of the pancreas and assess the beneficial effects of SIL on these changes. Forty-five rats were divided into control, cipralex, and cipralex plus SIL groups. During sacrifice, all rats and pancreases were weighed and the ratio of pancreatic weight (PW) to rat weight (RW) was calculated, blood samples were collected to estimate fasting glucose, insulin and amylase levels, the specimens were prepared for histological, immunohistochemical (inducible nitric oxide synthase [iNOS], tumour necrosis factor-alpha [TNF-α], caspase 3, proliferating cell nuclear antigen [PCNA], and anti-insulin antibody), and morphometrical studies. Cipralex group exhibited marked destruction of the pancreatic architecture of the exocrine and endocrine parts, with a dense collagen fiber deposition. Also, there is highly significant decrease (P<0.001) of PW/RT ratio, insulin, and amylase levels, the number and diameter of islets of Langerhans, the number of PCNA positive immunoreactive cells, and the number of insulin positive β-cells. Furthermore, a highly significant increase of glucose level, iNOS, TNF-α, and caspase-3 positive immunoreactive cells in the islets of Langerhans and acinar cells were observed. SIL improves the pancreatic histological architecture, weight loss, biochemical, and immunohistochemical analyses. Administering SIL is advantageous in managing cipralex induced pancreatic injury via its anti-inflammatory, antioxidant, and anti-apoptotic qualities.

Annexin I Stimulates Insulin Secretion through Regulation of Cytoskeleton and PKC Activity

  • Kang, Na-Na;Won, Jong-Hak;Park, Young-Min
    • Animal cells and systems
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    • v.13 no.1
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    • pp.17-23
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    • 2009
  • In previous studies, we found that Annexin I (Anx I) was co-secreted with insulin in response to glucose, and that extracellular Anx I stimulated the release of insulin via the Anx I binding site in rat pancreatic islets and the &-cell line. However, the role that Anx I plays in the insulin secretion was not established. Therefore, in this study, we evaluated the insulin secretion pattern in response to Anx I and the involvement of the cytoskeleton or PKC in Anx Istimulated insulin secretion in MIN6N8a cells. The peak time of insulin secretion in response to Anx I treatment corresponded with the second phase insulin secretion by glucose in the perifused pseudoislets. In addition, Anx I-stimulated insulin secretion was not affect by readily releasable pool depletion. Taken together, these findings indicate that Anx I treatment was associated with movement of the reserve pool of insulin. Furthermore, Anx I-stimulated insulin secretion was attenuated by treatment with a microfilament inhibitor, cytochalasin B, as well as by PKC down regulation. These results indicate that Anx I may be a regulator of second phase insulin secretion.

Hypoglycemic effect of a polyherbal aqueous extract in experimentally induced diabetic rats

  • Vasu, Vihas T.;Thaikoottathil, Jyoti V.;Gupta, Sarita
    • Advances in Traditional Medicine
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    • v.5 no.2
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    • pp.160-166
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    • 2005
  • The present study was carried out to investigate the hypoglycemic effect of a polyherbal aqueous extract (Curcuma longa Linn., Emblica officinalis Gaertn., Trigonella foenum-graecum Linn., Enicostemma littorale Blume) in alloxan-induced diabetic rats. Short term experiments showed a decrease in blood glucose levels at $2^{nd}\;hr$ of administration of the aqueous extract in alloxan-induced diabetic rats with increase in serum insulin levels. The extract did not show any effect on blood glucose or serum insulin levels in normoglycaemic rats. Treatment with the extract (1.5 g dry plant equivalent extarct/100 g body weight/day) for 20 days in diabetic rats showed a significant decrease in blood glucose and glycosylated haemoglobin levels and an increase in serum insulin levels. The aqueous extract also showed an enhanced glucose-induced insulin release at 11.1 mM glucose from isolated rat pancreatic islets. The extract did not show any toxicity at the particular dose used.

FURTHER PURIFIED GINSENG EXTRACT FRACTION (D-O-ANA) FOR INSULIN RELEASE AND ITS MODE OF ACTION COMPARED WITH THE ISOLATED RESIDUAL COMPONENTS (인삼성분 D-O-ANa이 인슐린 분비에 미치는 영향 및 작용기전에 관한연구)

  • KIMURA Masayasu;SUZUKI Jun;WAKI Isami;KIMURA Ikuko;TANAKA Osamu;MATSU-URA Hiromichi
    • Proceedings of the Ginseng society Conference
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    • 1984.09a
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    • pp.191-197
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    • 1984
  • A further purified fraction (D-O-ANa) was obtained from DPG 3-2 fraction of Ginseng Radix by complete removal of saponins, nucleosides, nucleic acid bases, amino acids, and sugars. D-O-ANa - induced insulin release was investigated to compare with that of DPG 3-2 and other isolated components. Among the sub fractions of DPG 3-2, D-O-ANa exhibited the most potent release of insulin with or without high concentrations of glucose, and it particularly enhanced the second phase of glucose-induced insulin release. DGP 3-2 potentiated significantly the glucose-induced insulin release from the isolated islets of diabetic mice at increasing concentrations of extracellular calcium ions (0.16 - 2.5 mM). A definite relationship was found between calcium $(^{45}Ca)$ uptake and insulin release. Ginsenoside $(G)-Rb_1\;and\;G-Rg_1$ did not enhance the glucose-induced insulin release. The effect of ginseng saponins was blocked by glucose (16.7 mM), being distinctly different from the glucose-potentiated effect of DPG 3-2. The insulin release effect of $G-Rg_1$ was unaffected by the presence or absence of extracellular $Ca^{2+}$ and theophylline. Adenosine also increased insulin release from isolated islets, but had no effect on perfused rat pancreas. Arginine stimulated insulin release less evidently than D-O-ANa, though arginineand adenosine-induced glucagon releases were more remarkable. In conclusion, D-O-ANa appears to be a major fraction in insulin release activity of ginseng and its mode of action may be related to $Ca^{2+}$ ion uptake. This physiological mechanism was distinct from that of the abnormal release induced by ginseng saponins.

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Effects of Multi-extracts of Mori Folium and of Exercise on Serum Lipid Profiles and Tissue Differentiation in Streptozotocin-induced Diabetic Rats

  • Ko, Young-Cheol;Seok, Hye-Jin;Song, Kyung-Hee
    • Nutritional Sciences
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    • v.6 no.4
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    • pp.209-215
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    • 2003
  • This research was performed to investigate the effects of the supplementation of multi-extracts of mori folium (MF) and of exercise on blood lipid profiles and tissue differentiation in streptozotocin (STZ)-induced diabetic rats. The animal groups consisted of a normal-control group, a STZ-control group, three STZ-induced diabetic groups supplemented ad libitum with various amounts of MF extracts (MF-720, MF-360, and MF-180 groups), and a STZ-induced diabetic group supplemented with MF-360 combined with exercise; eight male Sprague-Dawley rats, 4 weeks old, were assigned to each experimental group and were raised in the laboratory for a 10 week experimental period. The MF supplementation group showed a significant reduction in levels of serum total cholesterol and triglyceride compared to the STZ-control group. HDL-cholesterol levels were significantly increased in the MF supplementation group compared to STZ-control group. The ratio of HDL-cholesterol to total cholesterol was significantly higher in MF supplementation group compared to the STZ-control group. The Atherogenic Index (AI) values in the MF supplementation groups were found to be significantly lower than in the STZ-control group. Serum AST and ALT levels were significantly reduced in the MF-supplementation groups compared to the STZ-control group. Total cholesterol level in the liver tissue was significantly decreased in the MF-360 group and in the MF-360 + exercise group compared to the STZ-control group. In immunohistochemical staining of the pancreatic islets of the MF-supplemented groups, a significantly higher number of insulin-immunoreactive cells were observed compared to the STZ-control group. In the MF supplementation groups, Bowman's capsules were clearly observed as hypertrophy of the glomeruli was not obvious. In the MF supplementation groups, a relative reduction in the hypertrophy of the basement membrane of the glomeruli and a significant reduction in the mesangium were observed compared to the STZ-control group. The results of this study suggest that supplementation of MF has beneficial effect in improving plasma lipid and tissue metabolism in streptozotocin-induced rats.

Celastrol ameliorates cytokine toxicity and pro-inflammatory immune responses by suppressing NF-κB activation in RINm5F beta cells

  • Ju, Sung Mi;Youn, Gi Soo;Cho, Yoon Shin;Choi, Soo Young;Park, Jinseu
    • BMB Reports
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    • v.48 no.3
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    • pp.172-177
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    • 2015
  • Upregulation of pro-inflammatory mediators contributes to ${\beta}$-cell destruction and enhanced infiltration of immune cells into pancreatic islets during development of type 1 diabetes mellitus. In this study, we examined the regulatory effects and the mechanisms of action of celastrol against cytotoxicity and pro-inflammatory immune responses in the RINm5F rat pancreatic ${\beta}$-cell line stimulated with a combination of interleukin-1 beta, tumor necrosis factor-alpha, and interferon-${\gamma}$. Celastrol significantly restored cytokine-induced cell death and significantly inhibited cytokine-induced nitric oxide production. In addition, the protective effect of celastrol was correlated with a reduction in pro-inflammatory mediators, such as inducible nitric oxide synthase, cyclooxygenase-2, and CC chemokine ligand 2. Furthermore, celastrol significantly suppressed cytokine-induced signaling cascades leading to nuclear factor kappa B (NF-${\kappa}B$) activation, including $I{\kappa}B$-kinase (IKK) activation, $I{\kappa}B$ degradation, p65 phosphorylation, and p65 DNA binding activity. These results suggest that celastrol may exert its cytoprotective activity by suppressing cytokine-induced expression of pro-inflammatory mediators by inhibiting activation of NF-${\kappa}B$ in RINm5F cells.

Expression, Purification, and Characterization of C-Terminal Amidated Glucagon in Streptomyces lividans

  • Qi, Xiaoqiang;Jiang, Rong;Yao, Cheng;Zhang, Ren;Li, Yuan
    • Journal of Microbiology and Biotechnology
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    • v.18 no.6
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    • pp.1076-1080
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    • 2008
  • Glucagon, a peptide hormone produced by alpha-cells of Langerhans islets, is a physiological antagonist of insulin and stimulator of its secretion. In order to improve its bioactivity, we modified its structure at the C-terminus by amidation catalyzed by a recombinant amidase in bacterial cells. The human gene coding for glucagon-gly was PCR amplified using three overlapping primers and cloned together with a rat ${\alpha}$-amidase gene in plasmid pMGA. Both genes were expressed under control of the strong constitutive promoter of aph and secretion signal melC1 in Streptomyces lividans. With Phenyl-Sepharose 6 FF, Q-Sepharose FF, SP-Sepharose FF chromatographies and HPLC, the peptide was purified to about 93.4% purity. The molecular mass of the peptide is 3.494 kDa as analyzed by MALDI TOF, which agrees with the theoretical mass value of the C-terminal amidated glucagon. The N-terminal sequence of the peptide was also determined, confirming its identity with human glucagon at the N-terminal part. ELISA showed that the purified peptide amide is bioactive in reacting with glucagon antibodies.

Potential mechanism of anti-diabetic activity of Picrorhiza kurroa

  • Husain, Gulam Mohammed;Rai, Richa;Rai, Geeta;Singh, Harikesh Bahadur;Thakur, Ajit Kumar;Kumar, Vikas
    • CELLMED
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    • v.4 no.4
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    • pp.27.1-27.5
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    • 2014
  • Picrorhiza kurroa Royle ex Benth. (Scrophulariaceae) is a traditional Ayurvedic herb known as Kutki. It is used as a remedy for diabetes by tribes of North Eastern Himalayan region of India. Present study was conducted to explore the mechanism of antidiabetic activity of standardized aqueous extract of Picrorhiza kurroa (PkE). PkE (100 and 200 mg/kg/day) was orally administered to streptozotocin induced diabetic rats, for 14 consecutive days. Plasma insulin levels were measured and pancreas of rat was subjected to histopathological investigations. Glucose transporter type 4 (GLUT-4) protein content in the total membrane fractions of soleus muscle was estimated by Western blot analysis. Plasma insulin level was significantly increased along with concomitant increase in GLUT-4 content of total membrane fractions of soleus muscle of diabetic rats treated with extract. There was evidence of regeneration of ${\beta}$-cells of pancreatic islets of PkE treated group in histopathological examinations. PkE increased the insulin-mediated translocation of GLUT-4 from cytosol to plasma membrane or increased GLUT-4 expression, which in turn facilitated glucose uptake by skeletal muscles in diabetic rats.