Biological Activity
Bay K 8644, a dihydropyridine compound, is a specific L-type Ca2+ channel agonist. Bay K 8644 increases Ca2+ influx through sarcolemmal Ca2+ channels by increasing the open time of the channel[1].
In Vitro
In newborn rat ventricular cardiomyocytes, Bay K 8644 (1 μM) treatment increases L-type calcium current density in 2-day-old cells. The higher increase of L-type calcium current density by Bay K 8644 in 2-day- than in 7-day-old cultured cells could be interpreted as the result of a difference in the phosphorylation level of calcium channels for each stage of development[2].
In Vivo
A one time dose as low as 10 μg/kg of Bay K 8644 significantly elevates mean arterial pressure (MAP) in endotoxin-treated hypotensive rats while having minimal effects in normal rats. Bay K 8644 also causes a dose-dependent decrease in heart rate of 37% in endotoxin-treated rats and 39% in control rats[1].
References & source
[1]. H Satoh, et al. Bay K 8644 increases resting Ca2+ spark frequency in ferret ventricular myocytes independent of Ca influx: contrast with caffeine and ryanodine effects. Circ Res. 1998 Dec 14-28;83(12):1192-204.
[2]. J P Gomez, et al. Effects of Bay K 8644 on L-type calcium current from newborn rat cardiomyocytes in primary culture. J Mol Cell Cardiol. 1996 Oct;28(10):2217-29.
[3]. N Ives,et al. BAY k 8644, a calcium channel agonist, reverses hypotension in endotoxin-shocked rats. Eur J Pharmacol. 1986 Nov 4;130(3):169-75.
Published experimental findings depend on the model and assay conditions. They do not guarantee equivalent performance in every application. For laboratory research use only.