XB-IMG-123585
Xenbase Image ID: 123585
|
Figure 8. Apparent affinities for TRPM2 activation by intracellular Ca2+ and ADPR are not altered by replacing intracellular Na+ with K+. (A) Macroscopic TRPM2 current elicited in an inside-out patch bathed in a potassium gluconate–based solution by rapid sequential exposure to 1 and 32 µM [ADPR] (bar) in the presence of 125 µM Ca2+. Pipette [Ca2+] was ∼4 µM. (B) Normalized dose-response curve for current activation by ADPR in potassium gluconate solution containing 125 µM free Ca2+ (closed circles) and a fit by the Hill equation (solid line). (C) Macroscopic TRPM2 current from an inside-out patch superfused with potassium gluconate solution and 32 µM ADPR; exposure to ∼15 µM [Ca2+]i was bracketed by exposures to 125 µM Ca2+ (bars). Pipette [Ca2+] was ∼4 µM. (D) Dose-response curve for activation by [Ca2+]i in potassium gluconate solution containing 32 µM ADPR. Mean currents in test [Ca2+]i, normalized to the mean of the currents in bracketing 125-µM Ca2+ segments, were plotted against [Ca2+]i and fitted to the Hill equation. Pipette [Ca2+] was either ∼4 µM (closed circles and solid fit line) or 1 mM (open circles and dashed fit line). (B and D) Data are represented as mean ± SEM. Image published in: Csanády L and Törocsik B (2009) © 2009 Csanády and Törőcsik. This image is reproduced with permission of the journal and the copyright holder. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike license Larger Image Printer Friendly View |