Effect of praeruptorin C on spontaneous [Ca2+]i transients in cultured myocardial cells of neonatal rats.

AIMS

To study the effects of praeruptorin C (Pra-C) on [Ca2+]i transients in cultured neonatal myocardiocytes.

METHOD

Using Ca(2+)-sensitive fluorescent indicator, Fura 2-AM, spontaneous cytosolic Ca2+ transients were measured in cultured myocardial cells of neonatal rats.

RESULTS

Pra-C 10, 30 mumol.L-1 caused a decrease in the peak of Ca2+ transients. Pra-C 30 mumol.L-1 and 10-30 mumol.L-1 inhibited partly the stimulatory effects of CaCl2 4.8 mmol.L-1 and Bay k 8644 100 nmol.L-1 on peak Ca2+ transients, respectively. Pra-C did not cause any marked change in the basal [Ca2+]i level between beats. Pra-C inhibited the reduced [Ca2+]i transients after inhibition of sarcoplasmic reticulum Ca2+ release in ryanodine pretreated cells.

CONCLUSIONS

Pra-C inferred with the Ca2+ influx responsible for excitation-contraction coupling in myocardiocytes.