TABLE 1

Effect of UR-Po563 (1 µM) on force of contraction and beating rate in isolated perfused Langendorff hearts from H2-TG and WT (n=3–4, each). Hearts were perfused initially with buffer for about 30 minutes for stabilization and allowed to beat spontaneously. Then with a syringe, driven by an electric pump, UR-Po563 solution was added to the perfusion buffer. Force was measured with a hook applied to the apex cordis and fed into a computer. After 5 minutes of drug perfusion the whole heart was rapidly frozen with Wollenberger clamps precooled in liquid nitrogen.

WTH2-TG
BasalUR-Po563BasalUR-Po563
Force (mN)7.89 ± 1.288.95 ± 1.9511.49 ± 2.0720.46 ± 2.81*
Beating rate (bpm)308 ± 8.60321 ± 13.2351 ± 37.3391 ± 16.2
dF/dt max (mN/s)204.6 ± 43.8220.6 ± 36.1296 ± 42.5718 ± 90.9*
dF/dt min (mN/s)−151 ± 53.2−172 ± 56.5−230 ± 39.3−566 ± 52.7*

*P < 0.05 versus basal.

  • bpm, beats per minute.