Table 1.

Average changes in function and myocardial absorbance of the perfused rabbit heart as a result of adenosine

	Adenosine Concentration, μM
	0	4.4	16	38	72	117	n
Coronary vascular resistance, mmHg·min·ml−1
Unpaced	1.29 ± 0.19	1.25 ± 0.23	1.06 ± 0.19	0.79 ± 0.11	0.72 ± 0.08*	0.70 ± 0.07	6
Paced	1.11 ± 0.24	1.00 ± 0.19	0.85 ± 0.16	0.73 ± 0.13	0.68 ± 0.11*	0.68 ± 0.11	3
Coronary flow rate, ml/min
Unpaced	42 ± 5	47 ± 6	54 ± 7	64 ± 5	67 ± 5*	66 ± 4	8
Paced	39 ± 4	44 ± 4	55 ± 5	63 ± 5	66 ± 4*	65 ± 4	8
Aortic output, ml/min
Unpaced	126 ± 9	137 ± 9	140 ± 8	139 ± 7	133 ± 6†	130 ± 6	8
Paced	127 ± 11	146 ± 11	157 ± 10	157 ± 10	157 ± 9*	156 ± 9	8
Heart rate, beats/min
Unpaced	153 ± 12	144 ± 12	139 ± 11	130 ± 9	124 ± 9*†	122 ± 9	8
Paced	163 ± 14	163 ± 14	163 ± 14	163 ± 14	163 ± 14	163 ± 14	8
Oxygen consumption, μmol O2·min−1·g−1
Unpaced	5.9 ± 0.7	6.1 ± 0.7	6.3 ± 0.6	6.2 ± 0.6	5.9 ± 0.6†	5.7 ± 0.6	7
Paced	7.0 ± 0.7	7.8 ± 0.7	8.5 ± 0.8	8.4 ± 0.8	8.3 ± 0.8*	8.2 ± 0.7	6
Venous Po2, mmHg
Unpaced	53 ± 12	95 ± 24	161 ± 29	271 ± 30	318 ± 33*	331 ± 34	8
Paced	19 ± 8	35 ± 8	128 ± 29	218 ± 32	248 ± 30*	249 ± 29	8
Myoglobin (∆OD582)
Unpaced		0.009 ± 0.001	0.021 ± 0.002	0.032 ± 0.003	0.042 ± 0.003*†	0.048 ± 0.004	6
Paced		0.010 ± 0.001	0.019 ± 0.001	0.026 ± 0.003	0.031 ± 0.004*	0.034 ± 0.005	6
Cytochrome c, (∆OD550)
Unpaced		−0.005 ± 0.001	−0.011 ± 0.002	−0.017 ± 0.002	−0.020 ± 0.003*†	−0.022 ± 0.004	6
Paced		−0.004 ± 0.001	−0.008 ± 0.001	−0.011 ± 0.001	−0.013 ± 0.002*	−0.014 ± 0.002	6
Cytochrome aa3 (∆OD605)
Unpaced		−0.011 ± 0.001	−0.022 ± 0.002	−0.033 ± 0.003	−0.040 ± 0.003*†	−0.045 ± 0.004	6
Paced		−0.009 ± 0.001	−0.017 ± 0.002	−0.022 ± 0.003	−0.026 ± 0.004*	−0.029 ± 0.004	6

Data are means ± SE. Adenosine resulted in dose-dependent changes in cardiac function and chromophore absorbance. OD, optical density.

^*Adenosine (72 µM) was significantly different compared with control (no adenosine) in either condition;

^†adenosine (72 µM) in unpaced hearts was significant from 72 µM adenosine in paced hearts.