Description
BAY K8644 (71145-03-4) is an L-type Ca2+-channel activator with positive inotropic and vasoconstrictive effects.
Chemical Properties
yellow powder
Uses
An active L-type, voltage-gated calcium channel agonist
Definition
ChEBI: Methyl 2,6-dimethyl-5-nitro-4-[2-(trifluoromethyl)phenyl]-1,4-dihydropyridine-3-carboxylate is a pentasubstituted dihydropyridine carrying methoxycarbonyl, 2-(trifluoromethyl)phenyl and nitro substituents at positions 3, 4 and 5 respectively as well as two methyl substituents at positions 2 and 6. It is a dihydropyridine, a methyl ester, a C-nitro compound and a member of (trifluoromethyl)benzenes.
Biological Activity
L-type Ca 2+ -channel activator (EC 50 = 17.3 nM). Has positive inotropic, vasoconstrictive and behavioral effects in vivo . Separate enantiomers also available ((4R)-1,4-Dihydro-2,6-dimethyl-5-nitro-4-[2-trifluoromet hyl)phenyl]-3-pyridinecarboxylic acid methyl ester and (4S)-1,4-Dihydro-2,6-dimethyl-5-nitro-4-[2-trifluoromet hyl)phenyl]-3-pyridinecarboxylic acid methyl ester).
Biochem/physiol Actions
(±)-Bay K8644 is a 1,4-dihydropyridine (DHP) derivative and an agonist for L-type Ca2+ channels. However, it′s enantiomers (-)-BAY k8644 and (+)-BAY k8644 have opposing functionality with respect to Ca2+ channels as high-potency agonist and low-potency antagonist, respectively. (±)-Bay K8644 increases influx of Ca2+ specifically at voltage-gated calcium channels. It constricts blood vessels and heart contraction.
in vitro
it was demonstrated that bay k 8644 prolonged the mean ca2+ channel opening time in heart myocytes and neurones of spinal ganglia. an experiment using rat heart ventricles demonstrated that bay k 8644, at the final concentration of approximately 1 pm, had strong positive inotropic effect when added to the perfusion fluid. moreover, the addition of bay k 8644 to the chronic ethanol treatment significantly reduced the electrophysiological signs of withdrawal in the isolated hippocampal slices. [2, 3]
in vivo
study in mice demonstrated that bay k 8644 significantly ameliorated the ethanol withdrawal syndrome. when experimental animals were administered with an acute injection of bay k 8644, the convulsive behavior of mice could be monitored to increase for 2 hours. in addition, bay k 8644 was also reported to ameliorate hypotension in endotoxin-shocked rats. it could lead to a 37% decrease in heart rate of endotoxin-treated rats and 39% decrease in control rats in a dose-dependent manner. [3,4]
References
1) Schramm?et al. (1983)?Novel Dihydropyridines with positive inotropic action through activation of Ca2+ channels; Nature,?303?535
2) Yamamoto?et al. (1984)?Bay K8644 Differentiates between potential and receptor operated Ca2+ channels; Eur. J. Pharmacol.?102?555
3) Thomas?et al. (1985)?A dihydropyridine (Bay K 8644) that enhances calcium currents in guinea pig and calf myocardial cells. A new type of positive inotropic agent; Circ. Res.,?56?87
4) Shi?et al. (2009)?Induction of pluripotent stem cells from mouse embryonic fibroblasts by Oct4 and Klf4 with small molecule compounds; Cell Stem Cell,?3?568
