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
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