. Author manuscript; available in PMC: 2019 Jan 1.

Published in final edited form as: J Mol Cell Cardiol. 2017 Nov 17;114:175–184. doi: 10.1016/j.yjmcc.2017.11.011

Table 5.

Mouse ex vivo working hearts at human-like heart rate have preserved β-adrenergic responses

	Heart Rate (bpm)	LVPmax (mmHg)	LVP min (mmHg)	+dP/dt max (mmHg)	−dP/dt max (mmHg)	Stroke Volume (μL/mg)
Control	133.7±8.86	85.17±2.97	2.74±0.22	3705.04±176.84	−2592.51±91.03	0.271±0.015
ISO (2 nM)	226.2±9.41^*	114.59±4.63^*	1.71±0.43^*	9717.48±599.23^*	−4241.13±317.74^*	0.277±0.016

2 nM isoproterenol (ISO) increased heart rate in mouse ex vivo working hearts in the presence of 300 μM lidocaine. The preserved positive β-adrenergic responses were further shown by the increased LVPmax, +/−dP/dt and reduced LVPmin. Although the stroke volume was not changed due to the increased heart rate, cardiac output significantly increased in response to β-adrenergic stimulation as the function of increased heart rate (62.17±2.66 vs. 36.17±3.00 μL/mg, P<0.05). N = 6 hearts.

Values are presented as mean ± SE.

P<0.05 vs. untreated control in Student’s t test.