2-Aminoethoxydiphenyl borate

FIG. 2. Mechanism of phenylephrine (PE)-mediated wave-like [Ca2+] oscillations in the rabbit inferior vena cava. (A) PE-mediated [Ca2+]j oscillations are completely inhibited by 10 fiM cyclopiazonic acid (CPA), but the average [Ca2+ ]j remains elevated. (B) PE-mediated [Ca2+]j oscillations are abolished by 75 /iM 2-aminoethoxydiphenyl borate (2-APB). (C) Application of 10 piM nifedipine (Nif) reduced the frequency of PE-mediated [Ca2+]j oscillations while additional application of SKF96365 (SKF) completely abolished the remaining [Ca2+] oscillations. (D) Application of 100 /iM 2,4-dichlorobenzamil (2,4-DCB) completely inhibited nifedipine-resistant PE-induced [Ca2+]j oscillations and lowered the [Ca2+]j to a level that is slightly higher than baseline. Additional application of SKF96365 returned the [Ca2+]j level to baseline. (Experimental traces reproduced with permission from Lee et al 2001.)... 

Blaustein 2-aminoethoxydiphenyl borate (2-APB) is used as a selective blocker of InsP3 receptors. However, I think I have seen recent papers showing that 2-APB also blocks Ca2+ entry in some way. Do you think it blocks Ca2+ entry and reduces the tonic component in this way ... 

FIG. 2. Simultaneous recording of membrane currents and Ca2+ fluorescence. (A) Upper and lower traces indicate the time courses of membrane current and [Ca2+] respectively. Cells were voltage-clamped at — 60 mV. Pipette contained Cs aspartate internal solution supplemented with 50 M fura-2. (B) Expanded time-courses of membrane current and [Ca2+] form the dotted box in A. TG, thapsigargin 2-APB, 2-aminoethoxydiphenyl borate. 

Wu, J., N. Kamimura, T. Takeo, S. Suga, M. Wakui, T. Maruyama and K. Mikoshiba, 2000, 2-Aminoethoxydiphenyl borate modulates kinetics of intracellular Ca(2+) signals mediated by inositol 1,4,5-trisphosphate-sensitive Ca(2+) stores in single pancreatic acinar cells of mouse, Mol Pharmacol, 58, (6), pp. 1368-1374... 

Maruyama T, Kanaji T, Nakade S, Kanno T, Mikoshiba K (1997) 2APB, 2-aminoethoxydiphenyl borate, a membrane-penetrable modulator of Ins(l,4,5)P3-induced Ca2+ release. J Biochem (Tokyo) 122 498-505. 

Mg ji in the presence of Mg this occurred in a concentration dependent manner. Treatment with 2-aminoethoxydiphenyl borate attenuated [Mg +]i load and depletion caused by Na + - and Ca2- --free conditions. Neither the concentration of intracellular ATP nor pHj correlated with changes in [Mg +j in artery segments. ... 

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