Abstract
Pancreatic islets were isolated from noninbred ob/ob mice and used for evaluating how removal of extracellular Na+ affects 45Ca fluxes in the insulin-producing β cells. Isoosmotic replacement of Na+ with Li+ was less efficient in stimulating the incorporation of intracellular (La3+ nondisplaceable) 45Ca than substitution with choline+ or sucrose. Ample support for the significance of Na+-Ca2+ exchange for the net efflux of Ca2+ was obtained with the observation that Na+ deprivation markedly inhibited the 45Ca washout in a Ca2+-deficient medium. The inhibitory action of Na+ deficiency exceeded that obtained with 20 mM glucose. The 45Ca incorporated after removal of Na+ differed from that taken in response to glucose in not being exchanged with the Ca2+ entering the β cells during glucose stimulation and in appearing also in the postmicrosomal supernatant obtained by differential centrifugation.
| Original language | English |
|---|---|
| Pages (from-to) | 143-152 |
| Number of pages | 10 |
| Journal | Biochemical Medicine |
| Volume | 24 |
| Issue number | 2 |
| State | Published - Dec 1 1980 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
Cite this
Calcium and pancreatic β-cell function. XI. Modification of 45Ca fluxes by Na+ removal. / Hellman, B.; Andersson, T.; Berggren, P. O.; Rorsman, P.
In: Biochemical Medicine, Vol. 24, No. 2, 01.12.1980, p. 143-152.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Calcium and pancreatic β-cell function. XI. Modification of 45Ca fluxes by Na+ removal
AU - Hellman, B.
AU - Andersson, T.
AU - Berggren, P. O.
AU - Rorsman, P.
PY - 1980/12/1
Y1 - 1980/12/1
N2 - Pancreatic islets were isolated from noninbred ob/ob mice and used for evaluating how removal of extracellular Na+ affects 45Ca fluxes in the insulin-producing β cells. Isoosmotic replacement of Na+ with Li+ was less efficient in stimulating the incorporation of intracellular (La3+ nondisplaceable) 45Ca than substitution with choline+ or sucrose. Ample support for the significance of Na+-Ca2+ exchange for the net efflux of Ca2+ was obtained with the observation that Na+ deprivation markedly inhibited the 45Ca washout in a Ca2+-deficient medium. The inhibitory action of Na+ deficiency exceeded that obtained with 20 mM glucose. The 45Ca incorporated after removal of Na+ differed from that taken in response to glucose in not being exchanged with the Ca2+ entering the β cells during glucose stimulation and in appearing also in the postmicrosomal supernatant obtained by differential centrifugation.
AB - Pancreatic islets were isolated from noninbred ob/ob mice and used for evaluating how removal of extracellular Na+ affects 45Ca fluxes in the insulin-producing β cells. Isoosmotic replacement of Na+ with Li+ was less efficient in stimulating the incorporation of intracellular (La3+ nondisplaceable) 45Ca than substitution with choline+ or sucrose. Ample support for the significance of Na+-Ca2+ exchange for the net efflux of Ca2+ was obtained with the observation that Na+ deprivation markedly inhibited the 45Ca washout in a Ca2+-deficient medium. The inhibitory action of Na+ deficiency exceeded that obtained with 20 mM glucose. The 45Ca incorporated after removal of Na+ differed from that taken in response to glucose in not being exchanged with the Ca2+ entering the β cells during glucose stimulation and in appearing also in the postmicrosomal supernatant obtained by differential centrifugation.
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UR - http://www.scopus.com/inward/citedby.url?scp=0019126246&partnerID=8YFLogxK
M3 - Article
C2 - 7006599
AN - SCOPUS:0019126246
VL - 24
SP - 143
EP - 152
JO - Molecular Genetics and Metabolism
JF - Molecular Genetics and Metabolism
SN - 1096-7192
IS - 2
ER -