SNX482 selectively blocks P/Q Ca2+ channels and delays the inactivation of Na+ channels of chromaffin cells

Acetylcholine Release at Neuromuscular Junctions of Adult Tottering Mice Is Controlled by N-(Cav2.2) and R-Type (Cav2.3) but Not L-Type (Cav1.2) Ca2+Channels

“…Although our results support up-regulation of R-type Ca 2ϩ channels as a compensatory mechanism for the functional loss of P/Q-type channels at tg neuromuscular junctions, reports suggest that SNX 482 may not only block R-type but also P/Q- (Arroyo et al, 2003) and N-type channels (Neelands et al, 2000). However, our immunohistochemical studies correlate with the pharmacological studies in that ␣ 1B and ␣ 1E staining is clearly evident at tg neuromuscular junctions, lending credence to the notion that R-type channels are present at tg terminals and play an important role in ACh release.…”

Selectivity of Action of Pregabalin on Ca2+ Channels but Not on Fusion Pore, Exocytotic Machinery, or Mitochondria in Chromaffin Cells of the Adrenal Gland

“…1A). Because the plasma membrane concentration reached by a single therapeutic dose of 600 mg of pregabalin is approx- Arroyo et al, 2003;Beydoun et al, 2005) this concentration was chosen for the experiments of this study.…”

“…Nife (3 M), 200 nM -agatoxin IVA (-Aga IVA), and 1 M -conotoxin GVIA (-Ctx GVIA) were used to block Cav1, Cav2.1, and Cav2.2 channels, respectively. The action of pregabalin on Cav2.3 channels could not be investigated, because SNX-482, the selective Ca 2ϩ channel blocker available to inhibit Cav2.3 channels, also inhibits Cav2.1 channels in chromaffin cells (Arroyo et al, 2003).…”

CaV2.3 channel and PKCλ: new players in insulin secretion

“…The presence of the Ca V 2.3 channel in the mouse β cell was reported after the polypeptide SNX482, used as a Ca V 2.3 channel-selective blocker, was made available (10,11). It is known that SNX482 is capable of blocking other types of Ca V channels as well (12). Therefore, caution should be exercised when using this Ca 2+ channel blocker to define the role of native Ca V 2.3 channels in cells containing multiple types of Ca V channels.…”