“0.01-1 microM FSK had no effect on up-modulated currents, whereas high FSK rapidly and reversibly inhibited ICa, L by < or = 42% without affecting ICl.”
“High FSK also inhibited ICa, L in myocytes dialyzed with protein kinase A inhibitor.”
“Short (2-3 min) exposures to higher concentrations (10-100 microM) of FSK frequently had a multiphasic effect on ICa, L ; marked stimulation during the first minute quickly faded during the next 1-2 min, and removal of the drug caused secondary stimulation that lasted for several minutes.”
“We conclude that FSK inhibits cardiac ICa, L by reducing the availability of Ca2+ channels.”