- Franckowiak, G. et al. (1985) Eur. J. Pharmacol. 114, 223.
- Alomone Labs (R)(+)-Bay K8644 inhibits L-type CaV channels heterologously expressed in Xenopus oocytes.A. Time course of CaV1.2 (co-expressed with α2δ1 and β1 auxiliary subunits) peak current amplitude, elicited by 100 ms voltage ramp from holding potential of -100 mV to +50 mV, delivered every 10 seconds. Application of 1, 10 and 100 µM (R)(+)-Bay K8644 (#B-352) inhibits the CaV1.2 current (indicated by the horizontal bar). B. Representative current traces before and during application of 1, 10 and 100 µM (R)(+)-Bay K8644 as indicated.
L-type Ca2+ channels possess binding sites for at least three distinct organic drug types: dihydropyridines (DHP), phenylalkylamines (PAA), and benzothiazepines (BTZ). These binding sites are known to reside in the α1 subunit of the channel.
(R)(+)-Bay K8644 is a DHP L-type Ca2+-channel blocker with negative inotropic and vasodilatatory effects in vivo. (R)(+)-Bay K8644 shows opposite effects to (S)(-)-Bay K8644. The action of the of (R)(+)-Bay K8644 was studied in rat tail artery and guinea pig ileal longitudinal smooth muscle using pharmacologic and radioligand binding assays. (R)(+)-Bay K8644 inhibited the responses to KCI-induced depolarization with IC50 values of 16.1-25.6 nM1.