Bradykinin induced sustained anti–adrenergic actions in guinea pig heart muscle involves PKC

Figures & data

Figure 1.  Protocols for the papillary muscle experiments. BIM: bisindolylmaleimide 20 nM, BK: bradykinin 500 nM, ISO: isoproterenol 100 nM, WM: wortmannin 100 nM ↓: 3 min exposure to ISO.

Figure 2.  Contractile force amplitude in response to isoproterenol in papillary muscle treated with bradykinin in combination with inhibitors to PKC or PI3-kinase. BIM: bisindolylmaleimide 20 nM, BK: bradykinin 500 nM, ISO: isoproterenol 100 nM, WM: wortmannin 100 nM: p < 0.05 compared to control.

Table I.  Contractile force amplitude. Initial values.

	Stabilization		12 min exposure to test agent
	N	mN	mN
CTR ISO	6	0.71±0.06	0.58±0.06
BK	6	0.73±0.10	0.68±0.10
BK + BIM	7	0.74±0.10	0.65±0.09

(Mean±SEM). BIM: bisindolylmaleimide, BK: bradykinin, ISO: isoproterenol.

Figure 3.  Simulated guinea pig action papillary muscle potential illustrating how APD-10, APD-50 and APD-90 were determined. Time 0 was set at maximum rate of rise of phase 0 depolarization, baseline resting membrane potential was set as the average of a 20 ms sampling sequence at 50 kHz starting at time −25 ms.