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Age decline in the activity of the Ca2+-sensitive K+ channel of human red blood cells.
J Gen Physiol 2007; 129(5):429-36JG

Abstract

The Ca(2+)-sensitive K(+) channel of human red blood cells (RBCs) (Gardos channel, hIK1, hSK4) was implicated in the progressive densification of RBCs during normal senescence and in the mechanism of sickle cell dehydration. Saturating RBC Ca(2+) loads were shown before to induce rapid and homogeneous dehydration, suggesting that Gardos channel capacity was uniform among the RBCs, regardless of age. Using glycated hemoglobin as a reliable RBC age marker, we investigated the age-activity relation of Gardos channels by measuring the mean age of RBC subpopulations exceeding a set high density boundary during dehydration. When K(+) permeabilization was induced with valinomycin, the oldest and densest cells, which started nearest to the set density boundary, crossed it first, reflecting conservation of the normal age-density distribution pattern during dehydration. However, when Ca(2+) loads were used to induce maximal K(+) fluxes via Gardos channels in all RBCs (F(max)), the youngest RBCs passed the boundary first, ahead of the older RBCs, indicating that Gardos channel F(max) was highest in those young RBCs, and that the previously observed appearance of uniform dehydration concealed a substantial degree of age scrambling during the dehydration process. Further analysis of the Gardos channel age-activity relation revealed a monotonic decline in F(max) with cell age, with a broad quasi-Gaussian F(max) distribution among the RBCs.

Authors+Show Affiliations

Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, UK. jtt1000@cam.ac.ukNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17470662

Citation

Tiffert, Teresa, et al. "Age Decline in the Activity of the Ca2+-sensitive K+ Channel of Human Red Blood Cells." The Journal of General Physiology, vol. 129, no. 5, 2007, pp. 429-36.
Tiffert T, Daw N, Etzion Z, et al. Age decline in the activity of the Ca2+-sensitive K+ channel of human red blood cells. J Gen Physiol. 2007;129(5):429-36.
Tiffert, T., Daw, N., Etzion, Z., Bookchin, R. M., & Lew, V. L. (2007). Age decline in the activity of the Ca2+-sensitive K+ channel of human red blood cells. The Journal of General Physiology, 129(5), pp. 429-36.
Tiffert T, et al. Age Decline in the Activity of the Ca2+-sensitive K+ Channel of Human Red Blood Cells. J Gen Physiol. 2007;129(5):429-36. PubMed PMID: 17470662.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Age decline in the activity of the Ca2+-sensitive K+ channel of human red blood cells. AU - Tiffert,Teresa, AU - Daw,Nuala, AU - Etzion,Zipora, AU - Bookchin,Robert M, AU - Lew,Virgilio L, PY - 2007/5/2/pubmed PY - 2007/6/28/medline PY - 2007/5/2/entrez SP - 429 EP - 36 JF - The Journal of general physiology JO - J. Gen. Physiol. VL - 129 IS - 5 N2 - The Ca(2+)-sensitive K(+) channel of human red blood cells (RBCs) (Gardos channel, hIK1, hSK4) was implicated in the progressive densification of RBCs during normal senescence and in the mechanism of sickle cell dehydration. Saturating RBC Ca(2+) loads were shown before to induce rapid and homogeneous dehydration, suggesting that Gardos channel capacity was uniform among the RBCs, regardless of age. Using glycated hemoglobin as a reliable RBC age marker, we investigated the age-activity relation of Gardos channels by measuring the mean age of RBC subpopulations exceeding a set high density boundary during dehydration. When K(+) permeabilization was induced with valinomycin, the oldest and densest cells, which started nearest to the set density boundary, crossed it first, reflecting conservation of the normal age-density distribution pattern during dehydration. However, when Ca(2+) loads were used to induce maximal K(+) fluxes via Gardos channels in all RBCs (F(max)), the youngest RBCs passed the boundary first, ahead of the older RBCs, indicating that Gardos channel F(max) was highest in those young RBCs, and that the previously observed appearance of uniform dehydration concealed a substantial degree of age scrambling during the dehydration process. Further analysis of the Gardos channel age-activity relation revealed a monotonic decline in F(max) with cell age, with a broad quasi-Gaussian F(max) distribution among the RBCs. SN - 0022-1295 UR - https://www.unboundmedicine.com/medline/citation/17470662/Age_decline_in_the_activity_of_the_Ca2+_sensitive_K+_channel_of_human_red_blood_cells_ L2 - http://jgp.rupress.org/cgi/pmidlookup?view=long&pmid=17470662 DB - PRIME DP - Unbound Medicine ER -