Evidence for a Na+/Ca2+ exchange mechanism in frog skin epithelium

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Evidence for a Na+/Ca2+ exchange mechanism in frog skin epithelium. / Madsen, K H; Brodin, Birger; Nielsen, R.

In: Pflügers Archiv - European Journal of Physiology, Vol. 437, No. 2, 1999, p. 175-81.

Research output: Contribution to journalJournal articlepeer-review

Harvard

Madsen, KH, Brodin, B & Nielsen, R 1999, 'Evidence for a Na+/Ca2+ exchange mechanism in frog skin epithelium', Pflügers Archiv - European Journal of Physiology, vol. 437, no. 2, pp. 175-81.

APA

Madsen, K. H., Brodin, B., & Nielsen, R. (1999). Evidence for a Na+/Ca2+ exchange mechanism in frog skin epithelium. Pflügers Archiv - European Journal of Physiology, 437(2), 175-81.

Vancouver

Madsen KH, Brodin B, Nielsen R. Evidence for a Na+/Ca2+ exchange mechanism in frog skin epithelium. Pflügers Archiv - European Journal of Physiology. 1999;437(2):175-81.

Author

Madsen, K H ; Brodin, Birger ; Nielsen, R. / Evidence for a Na+/Ca2+ exchange mechanism in frog skin epithelium. In: Pflügers Archiv - European Journal of Physiology. 1999 ; Vol. 437, No. 2. pp. 175-81.

Bibtex

@article{ba35c9809706481fbd40dbb512f33ace,
title = "Evidence for a Na+/Ca2+ exchange mechanism in frog skin epithelium",
abstract = "In the present study we investigated the possible existence of a Na+/Ca2+ exchange mechanism in the basolateral membrane of the frog skin epithelium and whether such a mechanism plays a role in the regulation of transepithelial Na+ transport. Cytosolic calcium ([Ca2+]i) was measured with the probe fura-2 in a set-up in which pieces of tissue were mounted on the stage of an epifluorescence microscope. Na+ transport was measured as the amiloride-sensitive short-circuit current (Isc) using a conventional voltage clamp. Basal [Ca2+]i was 65+/-6 nM (n=15). Removal of Na+ from the mucosal solution had no effect on [Ca2+]i. When Na+ was removed from the serosal solution, [Ca2+]i increased biphasically to a peak of 220+/-38 nM (n=8, P=0.006). Readdition of Na+ to the serosal solution returned [Ca2+]i to control level. The serosal Na+ gradient and changes in [Ca2+]i were closely correlated; stepwise changes in serosal Na+ were followed by stepwise changes in [Ca2+]i. These observations indicate the existence of a Na+/Ca2+ exchange mechanism in the basolateral membrane of the frog skin epithelium. The transepithelial Na+ transport decreased from 13.2+/-1.8 to 9.2+/-1.5 microA cm-2 (n=8, P=0.049) when Na+ was omitted from the serosal solution. When this protocol was repeated in the absence of serosal Ca2+, Na+ transport decreased similarly from 16.7+/-1.7 to 11.6 +/-1. 8 microA cm-2 (n=6, P=0.004). We conclude that it is unlikely that the observed decrease in Isc after removal of serosal Na+ is due to an increase in [Ca2+]i per se.",
keywords = "Algorithms, Animals, Biological Transport, Calcium, Cytosol, Enzyme Inhibitors, Epithelium, Extracellular Space, Female, Rana temporaria, Skin, Sodium, Thapsigargin",
author = "Madsen, {K H} and Birger Brodin and R Nielsen",
year = "1999",
language = "English",
volume = "437",
pages = "175--81",
journal = "Pfl{\"u}gers Archiv - European Journal of Physiology",
issn = "0031-6768",
publisher = "Springer",
number = "2",

}

RIS

TY - JOUR

T1 - Evidence for a Na+/Ca2+ exchange mechanism in frog skin epithelium

AU - Madsen, K H

AU - Brodin, Birger

AU - Nielsen, R

PY - 1999

Y1 - 1999

N2 - In the present study we investigated the possible existence of a Na+/Ca2+ exchange mechanism in the basolateral membrane of the frog skin epithelium and whether such a mechanism plays a role in the regulation of transepithelial Na+ transport. Cytosolic calcium ([Ca2+]i) was measured with the probe fura-2 in a set-up in which pieces of tissue were mounted on the stage of an epifluorescence microscope. Na+ transport was measured as the amiloride-sensitive short-circuit current (Isc) using a conventional voltage clamp. Basal [Ca2+]i was 65+/-6 nM (n=15). Removal of Na+ from the mucosal solution had no effect on [Ca2+]i. When Na+ was removed from the serosal solution, [Ca2+]i increased biphasically to a peak of 220+/-38 nM (n=8, P=0.006). Readdition of Na+ to the serosal solution returned [Ca2+]i to control level. The serosal Na+ gradient and changes in [Ca2+]i were closely correlated; stepwise changes in serosal Na+ were followed by stepwise changes in [Ca2+]i. These observations indicate the existence of a Na+/Ca2+ exchange mechanism in the basolateral membrane of the frog skin epithelium. The transepithelial Na+ transport decreased from 13.2+/-1.8 to 9.2+/-1.5 microA cm-2 (n=8, P=0.049) when Na+ was omitted from the serosal solution. When this protocol was repeated in the absence of serosal Ca2+, Na+ transport decreased similarly from 16.7+/-1.7 to 11.6 +/-1. 8 microA cm-2 (n=6, P=0.004). We conclude that it is unlikely that the observed decrease in Isc after removal of serosal Na+ is due to an increase in [Ca2+]i per se.

AB - In the present study we investigated the possible existence of a Na+/Ca2+ exchange mechanism in the basolateral membrane of the frog skin epithelium and whether such a mechanism plays a role in the regulation of transepithelial Na+ transport. Cytosolic calcium ([Ca2+]i) was measured with the probe fura-2 in a set-up in which pieces of tissue were mounted on the stage of an epifluorescence microscope. Na+ transport was measured as the amiloride-sensitive short-circuit current (Isc) using a conventional voltage clamp. Basal [Ca2+]i was 65+/-6 nM (n=15). Removal of Na+ from the mucosal solution had no effect on [Ca2+]i. When Na+ was removed from the serosal solution, [Ca2+]i increased biphasically to a peak of 220+/-38 nM (n=8, P=0.006). Readdition of Na+ to the serosal solution returned [Ca2+]i to control level. The serosal Na+ gradient and changes in [Ca2+]i were closely correlated; stepwise changes in serosal Na+ were followed by stepwise changes in [Ca2+]i. These observations indicate the existence of a Na+/Ca2+ exchange mechanism in the basolateral membrane of the frog skin epithelium. The transepithelial Na+ transport decreased from 13.2+/-1.8 to 9.2+/-1.5 microA cm-2 (n=8, P=0.049) when Na+ was omitted from the serosal solution. When this protocol was repeated in the absence of serosal Ca2+, Na+ transport decreased similarly from 16.7+/-1.7 to 11.6 +/-1. 8 microA cm-2 (n=6, P=0.004). We conclude that it is unlikely that the observed decrease in Isc after removal of serosal Na+ is due to an increase in [Ca2+]i per se.

KW - Algorithms

KW - Animals

KW - Biological Transport

KW - Calcium

KW - Cytosol

KW - Enzyme Inhibitors

KW - Epithelium

KW - Extracellular Space

KW - Female

KW - Rana temporaria

KW - Skin

KW - Sodium

KW - Thapsigargin

M3 - Journal article

C2 - 9929556

VL - 437

SP - 175

EP - 181

JO - Pflügers Archiv - European Journal of Physiology

JF - Pflügers Archiv - European Journal of Physiology

SN - 0031-6768

IS - 2

ER -

ID: 37899848