scholarly journals Morphological analysis of isolated rat pancreatic islets cultured under standard culture technique and with biopolymer microstructured collagen‑containing hydrogel

2017 ◽  
Vol 19 (2) ◽  
pp. 90-97
Author(s):  
L. A. Kirsanova ◽  
N. V. Baranova ◽  
G. N. Bubentsova ◽  
V. I. Sevastianov
Keyword(s):  
Pancreatic Islets ◽  
Structural Integrity ◽  
Culture Technique ◽  
Isolated Pancreatic Islets ◽  
Rat Islets ◽  
Standard Culture ◽  
Islet Survival ◽  
Isolated Rat

Introduction. Extracellular matrix play an essential role in providing structural integrity and physiological support to Langerhans islets in pancreas. Imitation of the native microenvironment can be useful for viability of isolated pancreatic islets in vitro and in vivo. Aim. The purpose of this study was to characterize and compare the effect of biopolymer microstructured collagen-containing hydrogel (BMCH) on isolated rat islets survival. Materials and methods. Islets were isolated by classic collagenase techniques with some modifications. There were used hystological, immunofluorescence and immunohystochemistry methods. Results. Rat islets cultured with collagen-based gel don’t revealed destructive changes of structure and remained viabile 7 days incubation. Conclusion. Positive effect of BMCH to rat islet survival was revealed.

Culture Systems of Isolated Pancreatic Islets with Extracellular Matrix Biomimetics as Tissue-Engineered Constructs of the Pancreas

2021 ◽  
Author(s):  
Victor I Sevastianov ◽  
Natalia V Baranova ◽  
Lyudmila A Kirsanova ◽  
Anna S Ponomareva ◽  
Eugene A Nemets ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Pancreatic Islets ◽  
Human Pancreas ◽  
Isolated Pancreatic Islets ◽  
Tissue Specific ◽  
Culture Systems ◽  
Engineered Structures ◽  
The Creation

Abstract The creation of a tissue-engineered structure of the pancreas based on isolated pancreatic islets is hindered by problems associated with maintaining their viability and insulin-producing function. Both biopolymer and tissue-specific scaffolds can contribute to the preservation of the structure and function of pancreatic islets in vitro and in vivo. Comparative morphofunctional analysis in vitro of two different types of tissue-engineered structures of the pancreas, which represent culture systems of isolated islets with biomimetics of an extracellular matrix - a biopolymer collagen-containing scaffold and a tissue-specific scaffold obtained as a result of pancreatic decellularization, - was performed. The results showed that the use of scaffolds in the creation of a tissue-engineered design of the pancreas contributes not only to the preservation of the viability of the islets, but also to the prolongation of their insulin-producing functions, compared to the monoculture of the islets in vitro. A significant increase was found in the basal and stimulated (under glucose load) insulin concentrations in the tissue of engineered structures studied, at the same time the advantage of using a tissue-specific scaffold compared to a biopolymer collagen-containing scaffold was shown. We think that these studies will become a platform for creating a tissue-engineered design of the human pancreas for treatment of type 1 diabetes mellitus.

Rapid depletion of somatostatin in isolated mouse pancreatic islets after treatment with cysteamine

1985 ◽  
Vol 110 (2) ◽  
pp. 227-231 ◽  
Author(s):  
Birger Petersson ◽  
Claes Hellerström
Keyword(s):  
Pancreatic Islets ◽  
Insulin Release ◽  
Basal Insulin ◽  
Glucose Stimulation ◽  
Isolated Pancreatic Islets ◽  
Basal Release ◽  
Mouse Pancreatic Islets ◽  
Mouse Islets

Abstract. Cysteamine (CSH; β-mercaptoethylamine) is known to deplete pancreatic somatostatin without affecting the insulin or glucagon content. It may therefore be useful for studies of intra-islet regulation of hormone release. In the present study injection of CSH (60 mg/kg body weight) to mice decreased the somatostatin content of their isolated pancreatic islets to 50% in 1 h and 30% in 4 h as compared to islets of non-injected controls. Exposure of isolated mouse islets to CSH (100 μg/ml) for either 0.5 h followed by incubation in control medium for 3.5 h, or continuously for 4 h, decreased the somatostatin content to about 40% of the controls. There was no change in the islet content of insulin or glucagon. Islets pretreated with CSH (100 μg/ml) for 1 h in vitro showed a decreased glucose stimulation of both oxygen consumption and glucose oxidation. Measurements of insulin release after a similar preincubation of the islets indicated an increased basal release and an attenuated glucose stimulation. It is concluded that CSH rapidly decreases islet somatostatin both in vivo and in vitro. This depletion may lead to a loss of tonic inhibition by islet somatostatin on basal insulin release. It is, however, more plausible that the increased basal insulin release reflected a direct effect of CSH on the islet β-cells.

scholarly journals Morphofunctional characteristic of endocrine part of pancreas under affecting of γ-HCH

2020 ◽  
Vol 80 (4) ◽  
pp. 152-160
Author(s):  
G. Tusupbekova ◽  
◽  
G. Meiramov ◽  
Keyword(s):  
Blood Serum ◽  
Pancreatic Islets ◽  
Organic Pollutant ◽  
Immunoreactive Insulin ◽  
Specific Method ◽  
Β Cells ◽  
Isolated Pancreatic Islets ◽  
Experimental Animals

In the last decades of the twentieth century, in the national economy of many countries, organochlorine pesticides were most widely used, characterized by stability in the external environment, the ability to cumulate in various tissues of organisms. Lindane (the gamma isomer of hexachlorocyclohexane) is listed as a restricted persistent organic pollutant and is an ecotoxic substance with severe and chronic effects on the human body. The study of the effect of lindane on carbohydrate metabolism at the present stage is still insufficient. This fact led to the study of the effect of γ-HCH on the insulinogenic function of the pancreas in in vivo and in vitro experiments. In experiments in vivo, the animals of the experimental groups were once orally administered γ-HCH at a dose equal to 1/5 DL50. Isolated pancreatic islets, precipitated in vitro and fixed on mica plates, were exposed to γ-HCH in amounts equivalent to 1/5 to 1/4 DL50. Paraffin sections of pancreatic tissue from experimental and control animals were stained with aldehyde fuchsin according to Gomori, and tissue preparations were also examined by a highly specific method for detecting insulin in β-cells using diethylpseudoisocyanin staining, followed by examination of the preparations in the ultraviolet light of a luminescent microscope. The samemethods were used to study preparations of isolated pancreatic islet tissue on the 4th day of cultivation. The influence of orally administered γ-HCH on the level of immunoreactive insulin in the blood of experimental animals was also studied. The insulin level was determined by the enzymatic-immunological method. The concentration of IRI was established before the start of the experiment and 4-4.5 hours after acute inoculation. Results and their significance. In the study of stained preparations of the pancreas of experimental animals, numerous islets of ordinary sizes were revealed, the cytoplasm of which was filled with aldehyde-fuccin granularity in quantities indistinguishable from those observed by microscopy of preparations of control animals. The value of the fluorescence coefficient in the histofluorimetric study of the control and experimental preparations did not differ significantly. However, the content of IRI in the blood serum showed a distinct decrease in the first hours after priming. In experiments in vitro, when studying the effect of γ-HCH on cultured tissue, introduced into the nutrient medium on the second day, in the field of view of the microscope, single, small pancreatic islets were revealed. Their number on a constant area of the plates was significantly lower than the value of the same indicator in the study of control preparations. Thus it has been shown that γ-HCH does not affect the histostructure of the endocrine pancreas, but causes a significant decrease in IRI in the blood serum, as well as a change in the histochemical characteristics of cultured β-cells.

In vivo endotoxin and IL-1 potentiate insulin secretion in pancreatic islets

1990 ◽  
Vol 258 (4) ◽  
pp. R1070-R1077 ◽  
Author(s):  
M. R. Yelich
Keyword(s):  
Insulin Secretion ◽  
Pancreatic Islets ◽  
Interleukin 1 ◽  
Similar Extent ◽  
Isolated Pancreatic Islets ◽  
In Vitro Insulin Secretion ◽  
In Vivo Effects ◽  
Insulin Secretory Response

This study evaluated the in vivo effects of endotoxin and interleukin 1 (IL-1) on in vitro insulin secretion from perfused rat pancreases and isolated pancreatic islets. Glucose-induced insulin secretion was potentiated in pancreases obtained from rats 3 h after endotoxin or 30 min after IL-1. Studies using isolated pancreatic islets indicated that islet sensitivity to glucose was increased by either endotoxin or IL-1 to a similar extent, but there was no effect of endotoxin or IL-1 on the maximal insulin secretory response of islets to glucose. Insulin secretion was not potentiated in perfused pancreases obtained from rats only 30 min after treatment with endotoxin. These results suggest that in vivo treatment with either endotoxin or IL-1 potentiates insulin secretion by increasing islet sensitivity to glucose. In addition, because endotoxin is known to potently stimulate the production and secretion of IL-1 in vivo, the results lend support to the hypothesis that the effects of endotoxin on insulin secretion may be mediated partially by IL-1.

scholarly journals Comparative Analysis of the Influence of Extracellular Matrix Biomimetics on the Viability and Insulin-Producing Function of Isolated Pancreatic Islets

2021 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Pancreatic Islets ◽  
Structure And Function ◽  
Human Pancreas ◽  
Isolated Pancreatic Islets ◽  
Tissue Specific ◽  
And Function ◽  
Morphofunctional Analysis

The creation of a pancreas tissue-engineered construct based on isolated pancreatic islets is hindered by problems associated with maintaining their viability and insulin-producing function. Both biopolymer and tissue-specific scaffolds can contribute to the maintenance of the structure and function of pancreatic islets in vitro and in vivo. A comparative morphofunctional analysis in vitro of isolated pancreatic islets cultured with a biopolymer collagen-containing scaffold and a tissue-specific scaffold obtained as a result of pancreatic decellularization was performed. The results showed that the use of the scaffolds contributes not only to the maintenance of the cultured islets viability, but also to the prolongation of their insulin-producing functions, compared to the islets monoculture in vitro. A significant increase was found in basal and stimulated (under glucose loading) insulin secreted by the islets cultured with the scaffolds. At the same time, the advantage of using a tissue-specific scaffold in comparison with a biopolymer collagen-containing scaffold was shown. We think that these studies will become a platform for creating a human pancreas tissue-engineered design for the treatment of type 1 diabetes.

Hormonal and non-hormonal protein biosynthesis in the pancreatic beta cell of the intact rat after prolonged hyperglycaemia

1984 ◽  
Vol 107 (3) ◽  
pp. 382-389 ◽  
Author(s):  
J. Logothetopoulos ◽  
Nancy Valiquette
Keyword(s):  
Beta Cell ◽  
Pancreatic Islets ◽  
Protein Biosynthesis ◽  
Pancreatic Beta Cell ◽  
Enzymatic Digestion ◽  
Insulin Biosynthesis ◽  
Isolated Pancreatic Islets ◽  
Pancreatic Cells

Abstract. We examined the relative changes in the rates of biosynthesis of (pro)insulin and of non-hormonal beta cell proteins in rats with pronounced hyperglycaemia for up to several days. Labelling of pancreatic cells in vivo eliminated certain pitfalls that we encountered when isolated pancreatic islets from these rats were labelled in vitro. Rats were infused with glucose or buffer solutions for 24 and 72 h. Glucose-infused rats had sustained hyperglycaemia throughout the infusion periods. l[4,5-3H]leucine or l[2,3-3H]tryptophan (an amino acid absent from proinsulin) was injected iv 30 min before the rats were killed. Pancreatic islets were isolated by enzymatic digestion of the pancreas. Pancreatic islets from the rats injected with [3H]leucine were processed for measurement of [3H]proinsulin and [3H]insulin by a double antibody immunoprecipitation procedure. Islets from rats injected with [3H]tryptophan were processed for autoradiography, in order to assess the incorporation of label into non-hormonal sedentary beta cell proteins. Incorporation of [3H]leucine into proinsulin and insulin per beta cell was estimated to be about 2–2.5 (24 h infusion) and 3.5–4 (72 h infusion) times greater in the hyperglycaemic than in normoglycaemic rats. Incorporation of [3H]tryptophan into non-hormonal beta cell proteins showed similar increments in the hyperglycaemic rats. Contrary to our expectation these results indicate that glucose does not exert a significant preferential effect on insulin biosynthesis even after sustained stimulation of the beta cells. Instead, glucose seems to increase equally the incorporation of labelled amino acids into proinsulin and into non-hormonal, beta cell proteins.

Diazoxide pretreatment improves pancreatic islet survival in vitro and functionality in vivo

2018 ◽  
Author(s):  
Michiel Nijhoff ◽  
Francoise Carlotti ◽  
Marten Engelse ◽  
Koning Eelco de
Keyword(s):  
Pancreatic Islet ◽  
Islet Survival

Studies of Metabolism Mediated Mutagenicity In Vitro

1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 243-250
Author(s):  
Dag Jenssen ◽  
Lennart Romert
Keyword(s):  
Cell Lines ◽  
Biological Effects ◽  
Animal Experiments ◽  
Culture Technique ◽  
Organ Perfusion ◽  
Isolated Cells ◽  
Toxicological Effect ◽  
In Vitro Methods

To understand the cause of the biological effects of xenobiotic metabolism in mammals, investigators have traditionally performed animal experiments by comparing the results of biochemical methods, such as measurement of enzyme activity analysis of the metabolites produced, with the observed toxicological effect. This article deals with in vitro methods for genotoxicity combined with drug metabolising preparations at the organelle, cell or organ levels, as exemplified by microsome preparations, isolated cells/cell lines and organ perfusion systems, respectively. The advantage of some of these methods for studying metabolism-mediated mutagenicity is that the measured endpoint reflects not only the bioactivating phase I reactions, but also the detoxifying phase II reactions, and the transfer of the non-conjugated reactive metabolites to other cells and their ability to cause mutations in these cells. In vivo, all these events are important factors in the initiation of cancer. A mechanistic advantage of the methods for metabolism-mediated mutagenicity in vitro is that the relevance of the different steps in metabolism for the mutational events can seldom be investigated in an in vivo assay. Furthermore, human studies can easily be performed using the co-culture technique with isolated human cells or cell lines.

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