Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    The dynamics of insulin release from mouse pancreatic islet cells in suspension (1976)
    Springer
    Pflügers Archiv 366 (1976), S. 185-188 
    Details
    ISSN: 1432-2013
    Keywords: Insulin release ; Pancreatic β-cells ; β-Cells in suspension ; Intact pancreatic islets ; Glucose oxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The overall dynamics of glucose-induced insulin release was strikingly similar in dispersed cells and intact islets perifused in parallel. Both preparations exhibited a latency of 1–2 min, after which period there was a brisk rise of insulin release followed by a sustained second phase. During the second phase, insulin release from dispersed cells attained a stable plateau rate, whereas the release from intact islets continued to rise. Epinephrine (1 μM) inhibited the release in both preparations, but the return to basal rate was faster in the dispersed cells than in the intact islets. The dispersed cells oxidized glucose at a constant rate for at least 60 min; the glucose oxidation was markedly sensitive to changes of the glucose concentration in the range of 3–20 mM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00585876
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Stimulation and inhibition of insulin release by an amino-reactive probe of plasma membrane (1973)
    Springer
    The journal of membrane biology 14 (1973), S. 135-142 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary 4-Acetamido-4′-isothiocyanostilbene-2,2′-disulphonic acid (SITS), an amino-reacting probe of plasma membranes, stimulated the release of insulin from micro-dissected pancreatic islets ofob/ob-mice. This effect of SITS was inhibited by adrenaline or by calcium deficiency. SITS did not inhibit the insulin-releasing action of glucose or leucine but rather potentiated the effect of glucose. In contrast, SITS markedly depressed the insulin secretory response to chloromercuribenzene-p-sulphonic acid. It is suggested that by reacting with the plasma membranes SITS may induce secretagogic ionic fluxes in the β-cells. In addition, SITS apparently inhibits the secretagogic recognition of chloromercuribenzene-p-sulphonic acid, presumably by preventing the organic mercurial from reacting with certain membrane thiol groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01868074
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    45Ca2+ uptake by dispersed pancreatic islet cells: Effects ofd-glucose and the calcium probe, chlorotetracycline (1979)
    Springer
    Pflügers Archiv 381 (1979), S. 281-285 
    Details
    ISSN: 1432-2013
    Keywords: Calcium uptake ; Chlorotetracycline ; Dispersed cells ; Islets of Langerhans ; Pancreatic β-cells ; Pancreatic Islets
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Uptake of45Ca2+ was studied in dispersed pancreatic islet cells from non-inbredob/ob-mice. Like whole islets the dispersed cells responded to 20 mMd-glucose with a markedly increased45Ca2+-labeling of both the lanthanum-nondisplaceable and the lanthanum-displaceable calcium pools. The pronounced effect ofd-glucose could not be reproduced with 3-O-methyl-d-glucose,l-glucose,d-mannose,l-leucine, ord-leucine; however,45Ca2+ uptake was greater in the presence ofl-leucine as compared withd-leucine.45Ca2+ uptake by dispersed cells or whole islets was stimulated severalfold by 100 μM or more chlorotetracycline. At the concentration of only 10 μM, chlorotetracycline had no effect on whole islets and partially inhibited45Ca2+ uptake by the dispersed cells. The ability ofd-glucose to stimulate45Ca2+ uptake by islets or dispersed cells remained in the presence of 10 μM chlorotetracyline. Islet cell suspensions apparently represent a valid model for studying how Ca2+ interacts with the cells. However, when using chlorotetracycline as fluorescent Ca2+ probe, attention must be paid to its potential ionophoric activity. At only 10 μM, the drug seems to monitor a peripheral pool of Ca2+, some of which may reside in normal transport channels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00583260
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Ultrastructure and membrane permeability of cultured pancreaticβ-cells exposed to alloxan or 6-hydroxydopamine (1984)
    Springer
    Virchows Archiv 404 (1984), S. 31-38 
    Details
    ISSN: 1432-2307
    Keywords: Alloxan ; Culture ; Electron microscopy ; 6-Hydroxydopamine ; Pancreaticβ-cells ; Stereology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stereological techniques on electron microscopy micrographs were used to evaluate the morphological changes of cultured isletβ cells that had been exposed to alloxan or 6-hydroxydopamine. Trypan Blue exclusion by cells cultured for 3 days indicated that the cells were 100% viable. Electron microscopy revealed that nearly all of the surviving cultured cells wereβ cells. Exposure to 5 mmol/l alloxan or 1–5 mmol/l 6-hydroxydopamine for 10 or 30 min caused a general swelling of the cultured cells with a concomitant swelling of mitochondria and nuclei. The size of the secretory granules was not affected by the drugs. Only 3–10% of the cells excluded Trypan Blue after exposure to 5 mmol/l alloxan or 6-hydroxydopamine. The data conform with the hypothesis that a primary action of alloxan and 6-hydroxydopamine is at the plasma membrane level ofβ cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00704248
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Superoxide dismutase is a prophylactic against alloxan diabetes (1981)
    [s.l.] : Nature Publishing Group
    Nature 294 (1981), S. 158-160 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Fig. 1 Blood glucose concentrations in uninjected mice (0 h) and in mice intravenously injected with 25 (), 50 (O) or 75 () mg alloxan per kg body weight. Alloxan monohydrate (U.S. Biochemical Corporation) was dissolved in a salt-balanced Krebs-Ringer buffer that had been adjusted to pH 4.0 by the ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/294158a0
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Effect of Glucagon on the Alkaline Phosphatase Activity in the Pancreatic Islets of Rats (1966)
    [s.l.] : Nature Publishing Group
    Nature 209 (1966), S. 409-410 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Male Sprague Dawley rats, weighing about 95 g and allowed free access to food and water, were separated into two groups: (1) Ten rats received subcutaneous injections of glucagon (Eli Lilly and Co.) dissolved in glycine sodium hydroxide-sodium chloride buffer (0.1 M, pH 9.6), each injection ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/209409a0
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Kinetics of glucose 6-phosphatase in pancreatic islets as revealed by staining histochemistry (1969)
    Springer
    Histochemistry and cell biology 19 (1969), S. 355-362 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Glucose 6-phosphate hydrolysis in pancreatic islets of mice was visualized by the Gomori technique. Staining intensities were quantitatively assayed in a microscope photometer, and enzyme activities were expressed in arbitrary units, after correction of optical densities according to lead sulfide standards. Glucose 6-phosphate was most rapidly split at a pH of about 6.7. At this pH level there was a low rate of β-glycerophosphate hydrolysis, the ratio between the activities toward the two substrates (40 mM) being 4.0. In contrast to glucose 6-phosphate, β-glycerophosphate was more rapidly split at pH 5.0 than at pH 6.7. Preincubation of the cryostat sections at pH 5.0 for 15—30 min inactivated the glucose 6-phosphate-splitting activity. Inactivation of the enzyme activity toward glucose 6-phosphate also occurred during brief fixation of the sections in glutaraldehyde or formalin. The apparent K m for glucose 6-phosphate was 1–5 mM in the islets but in the order of 20 mM in the acinar tissue. Glucose was a potent inhibitor of glucose 6-phosphate hydrolysis, the apparent K m being strikingly increased by the sugar. These results support previous biochemical evidence for the presence of glucose 6-phosphatase in the pancreatic islets of mice. The kinetics of the enzyme in the cryostat section are furthermore consistent with the hypothesis that glucose 6-phosphatase is part of the β-cell's glucoreceptor mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00279684
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Direct fluorophotometric recording of enzyme kinetics in cryostat sections (1970)
    Springer
    Histochemistry and cell biology 21 (1970), S. 307-313 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A technique is described for the monitoring of enzyme-catalyzed pyridine nucleotide reduction in cryostat sections. By virtue of the native fluorescence of NADPH the kinetics of glucose 6-phosphate dehydrogenase in the mouse endocrine pancreas could be studied in a microscope fluorophotometer. The development of fluorescence was most rapid at a pH of about 8.0. Apparent K mvalues were 0.2 mM for glucose 6-phosphate and 2 mM for NADP. The reaction was enhanced by MgCl2 (optimum concentration of about 2 mM) but insensitive to KCN and oxygen. The rates of fluorescence development appeared unaffected by NADPH diffusion. The observed K mvalues are higher than those obtained by biochemical analysis of homogenized pancreatic islets. It is suggested that this discrepancy is due to the relative morphological integrity of the cryostat section. If the present data are more representative of the properties of the enzyme in the living cell than are the values obtained with disintegrated tissue, the phosphogluconate pathway in the pancreatic β-cells could be regulated by both glucose 6-phosphate and NADP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00280900
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Transport of 3-O-methyl-d-glucose into mammalian pancreatic β-cells (1973)
    Springer
    Pflügers Archiv 340 (1973), S. 51-58 
    Details
    ISSN: 1432-2013
    Keywords: 3-O-methyl-d-glucose ; Membrane Transport ; Pancreatic Islets ; Pancreatic β-Cells ; Insulin Release ; Glucose Receptor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The transport and oxidation of 3-O-methyl-d-(U-14C)glucose was studied in microdissected pancreatic islets of obese-hyperglycemic mice. There was no significant production of14CO2 during incubation for 2 h. A comparison with the uptake of sucrose and mannitol indicated that 3-O-methyl-d-glucose was uniformly distributed across the β-cell plasma membrane. Externald-glucose inhibited the entry of 3-O-methyl-d-glucose and caused a significant net loss of 3-O-methyl-d-glucose from islets equilibrated with this compound. The transport of 3-O-methyl-D-glucose was also markedly reduced in the presence of phlorizin or phloretin, whereasd-mannoheptulose ord-glucosamine exerted a slight inhibition. The results support our hypothesis that the transport ofd-glucose into the pancreatic β-cells is carriermediated, and indicate that 3-O-methyl-d-glucose is a non-metabolizable substrate for this carrier in the pancreatic islets. Since in contrast tod-glucose 3-O-methyl-d-glucose does not stimulte insulin release from the type of islets used, the secretagoric recognition system ford-glucose is probably not identical with the membrane transport system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00592196
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Effects of Na+, K+ and Mg2+ on45Ca2+ uptake by pancreatic islets (1978)
    Springer
    Pflügers Archiv 378 (1978), S. 93-97 
    Details
    ISSN: 1432-2013
    Keywords: Calcium uptake ; Insulin release ; Islets of Langerhans ; Lanthanum ; Magnesium ; Pancreatic islets ; Potassium ; Sodium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Microdissected pancreatic islets of noninbredob/ob-mice were used to study ionic effects on the lanthanum-nondisplaceable45Ca2+ uptake by islet cells. Omission of Mg2+ from the incubation medium had no effect, but the45Ca2+ uptake was increased by omission of Na+ and decreased by omission of K+. Excess Mg2+ (1.2–15 mM) inhibited and excess K+ (4.7–25 mM) stimulated the45Ca2+ uptake in a concentration-dependent manner. Stimulation of45Ca2+ uptake in Na+-deficient islets was associated with an enhancement of the basal insulin release. Total abolishment of glucose-stimulated45Ca2+ uptake in K+-deficient islets did not preclude a significant secretory response to glucose. It is concluded that the lanthanum-nondisplaceable45Ca2+ uptake shows a partial correlation to insulin release.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00584440
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...