APB

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.)... 

Sanders I thought there was a report of TRP channels being blocked by 2-APB. 

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. 

Fig. 5. Effect of WH on [Ca +], in Ang II-, CaCU or Bay K8644-stimulated VSMC. Ang II (10 UM)-induced [Ca " ]/ elevation (a) in Fura-2/AM-loaded VSMC was measured in the absence (Control) or presence of WH (300 juM). One pM PD 123177 as an AT2-receptor antagonist was added 10 min before Ang II addition. CaCf (2.5 mM) was added to VSMC treated with 2-APB (200 /xM IP3-R blocker)-containing Ca free PSS buffer (b). Effect of WH on [Ca ]/ in Bay K8644-stimulated VSMC was measured using a con-focal microscope and a fluorescent spectrometer (c). Bay K8644 (50 /xM)-induced [Ca ]/ elevation in VSMC was measured in the absence (Control) or presence of WH (300 /xM).

Enfissi, A., Prigent, S., Colosetti, P. and Capiod, T., 2004, The blocking of capacitative calcium entry by 2-aminoethyl diphenylborate (2-APB) and carboxyamidotriazole (CAI) inhibits proliferation in Hep G2 and Huh-7 human hepatoma cells. Cell Calcium 36, 459-467. 

Influx of Ca2+ through a-LTX pores might explain Ca2+-dependent secretion, but not the bursts of miniatures. These may be due to Ca2+ waves caused by activation of phospholipase C (PLC) (Vicentini and Meldolesi 1984 Davletov et al. 1998) and release of intracellular Ca2+ (Ca2+,). In fact, U73122 (blocks PLC activation by G proteins), thapsigargin (depletes Ca2+ stores), and 2-APB (inhibits activation of Ca2+ stores) block a-LTX action (Davletov et al. 1998 Ashton et al. 2001 Capogna et al. 2003), impheating a G protein cascade in Ca2+-dependent toxin-induced release. 

As shown in Table 7.1, B3LYP/6-31G calculations reproduce adequately the activation energies of Cope reactions. These calculations confirm (Table 7.2, APB in kcal... 

This paper describes the reduction of hypoxic but not hypercapnic chemosensory discharge of not carotid body key cell permanent IP, inhibitors, 2-aminocthoxydiphenylgorene (2-APB, 50-200 pM) in a dose-dependent way. 

Rat carotid sinus nerve activity is diminished by 2-APB during hypoxia (From Roy et al., 2006)... 

Glomus cell responses (a) Oligomycin abolished the calcium response to hypoxia (Hx), but exaggerated the same to hypercapnia, (b) 2-APB (IP3 antagonist) drastically reduced (From Lahiri, 2004)... 

Roy A, Mokashi A, Baby SM, DiGiulio C, Lahiri S. 2006. 2-APB and curcumin inhibit the hypoxic but not the hypercapnic carotid chemosensory discharge, (communicated). 

D. (2007) IP3 receptor antagonist, 2-APB, attenuates cisplatin induced Ca +-influx in HeLa-S3 cells and prevents activation of cal-pain and induction of apoptosis. Brit J Pharmacol, 151, 1176-1186. 

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