Alloxan cytotoxicity in vitro : Inhibition of rubidium ion pumping in pancreatic β cells
Idahl, L. A. ; Lernmark, A. LU
; Sehlin, J
and Täljedal, I. B.
(1977)
In Biochemical Journal
162(1).
p.9-18
- Abstract
- Exposing micro-dissected pancreatic islets of non-inbred ob/ob mice to 2-5 mM-alloxan for 10 min decreased the ability of the islets to accumulate Rb+. Rb+ accumulation in pieces of exocrine pancreas was unaffected by alloxan. When islets were treated with alloxan in the presence of 2-20 mM-D-glucose, the Rb+-accumulating ability was protected in a dose-dependent manner. The protective action of D-glucose was reproduced with 3-O-methyl-D-glucose but not with L-glucose or D-mannoheptulose; mannoheptulose prevented D-glucose from exerting its protective action. The inhibition of Rb+ accumulation was due to a decreased inward pumping, since alloxan did not affect Rb+ efflux from pre-loaded islets. The inhibitory effect of alloxan had a... (More)
- Exposing micro-dissected pancreatic islets of non-inbred ob/ob mice to 2-5 mM-alloxan for 10 min decreased the ability of the islets to accumulate Rb+. Rb+ accumulation in pieces of exocrine pancreas was unaffected by alloxan. When islets were treated with alloxan in the presence of 2-20 mM-D-glucose, the Rb+-accumulating ability was protected in a dose-dependent manner. The protective action of D-glucose was reproduced with 3-O-methyl-D-glucose but not with L-glucose or D-mannoheptulose; mannoheptulose prevented D-glucose from exerting its protective action. The inhibition of Rb+ accumulation was due to a decreased inward pumping, since alloxan did not affect Rb+ efflux from pre-loaded islets. The inhibitory effect of alloxan had a latency of about 1 min, as revealed by experiments with dispersed islet cells in suspension. Alloxan-treated islets showed only a marginal decrease in ATP and no change in glucose 6-phosphate concentration. Although alloxan slightly decreased the hydrolysis of ATP in a subcellular fraction enriched in plasma membranes, this effect could not be attributed to a ouabain-sensitive adenosine triphosphatase. The plasma membranes exhibited a K+-activated hydrolysis of p-nitrophenyl phosphate; this enzyme activity too was insensitive to alloxan. Glucose may protect the univalent-cation pump by preventing permeation of alloxan via a path coupled to the hexose-transport system. Inhibition of the pump may be fundamental to the induction of alloxan-diabetes. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/62e31e6c-4ab3-488a-8d2e-a74cac57f0d4
- author
- Idahl, L. A.
; Lernmark, A.
LU
; Sehlin, J
and Täljedal, I. B.
- publishing date
- 1977-01-01
- type
- Contribution to journal
- publication status
- published
- in
- Biochemical Journal
- volume
- 162
- issue
- 1
- pages
- 10 pages
- publisher
- Portland Press
- external identifiers
-
- scopus:0017577357
- pmid:192215
- ISSN
- 0264-6021
- DOI
- 10.1042/bj1620009
- language
- English
- LU publication?
- no
- id
- 62e31e6c-4ab3-488a-8d2e-a74cac57f0d4
- date added to LUP
- 2019-09-18 12:10:08
- date last changed
- 2024-03-13 08:07:23
@article{62e31e6c-4ab3-488a-8d2e-a74cac57f0d4,
abstract = {{Exposing micro-dissected pancreatic islets of non-inbred ob/ob mice to 2-5 mM-alloxan for 10 min decreased the ability of the islets to accumulate Rb+. Rb+ accumulation in pieces of exocrine pancreas was unaffected by alloxan. When islets were treated with alloxan in the presence of 2-20 mM-D-glucose, the Rb+-accumulating ability was protected in a dose-dependent manner. The protective action of D-glucose was reproduced with 3-O-methyl-D-glucose but not with L-glucose or D-mannoheptulose; mannoheptulose prevented D-glucose from exerting its protective action. The inhibition of Rb+ accumulation was due to a decreased inward pumping, since alloxan did not affect Rb+ efflux from pre-loaded islets. The inhibitory effect of alloxan had a latency of about 1 min, as revealed by experiments with dispersed islet cells in suspension. Alloxan-treated islets showed only a marginal decrease in ATP and no change in glucose 6-phosphate concentration. Although alloxan slightly decreased the hydrolysis of ATP in a subcellular fraction enriched in plasma membranes, this effect could not be attributed to a ouabain-sensitive adenosine triphosphatase. The plasma membranes exhibited a K+-activated hydrolysis of p-nitrophenyl phosphate; this enzyme activity too was insensitive to alloxan. Glucose may protect the univalent-cation pump by preventing permeation of alloxan via a path coupled to the hexose-transport system. Inhibition of the pump may be fundamental to the induction of alloxan-diabetes.}},
author = {{Idahl, L. A. and Lernmark, A. and Sehlin, J and Täljedal, I. B.}},
issn = {{0264-6021}},
language = {{eng}},
month = {{01}},
number = {{1}},
pages = {{9--18}},
publisher = {{Portland Press}},
series = {{Biochemical Journal}},
title = {{Alloxan cytotoxicity in vitro : Inhibition of rubidium ion pumping in pancreatic β cells}},
url = {{http://dx.doi.org/10.1042/bj1620009}},
doi = {{10.1042/bj1620009}},
volume = {{162}},
year = {{1977}},
}