Table 1.

Protocol 1. Forearm and systemic haemodynamics

Condition	Forearm blood flow (ml min−1)	Mean arterial pressure (mmHg)	Forearm vascular conductance (ml min−1 (100 mmHg)−1)	Heart rate (beats min−1)
A. Phenylephrine trials
Baseline
Adenosine	30 ± 4	92 ± 3	32 ± 4	56 ± 3
Exercise	26 ± 4	94 ± 3	28 ± 4	55 ± 4
ATP	29 ± 5	92 ± 2	31 ± 5	54 ± 4
Pre-phenylephrine
Adenosine	143 ± 16*	93 ± 3	156 ± 19*	57 ± 3
Exercise	154 ± 13*	96 ± 3	160 ± 12*	60 ± 4*
ATP	138 ± 19*	94 ± 2	149 ± 21*	56 ± 3
Phenylephrine
Adenosine	89 ± 9*†	98 ± 3*	92 ± 10*†	56 ± 3
Exercise	136 ± 12*†‡	96 ± 3	141 ± 10*†‡	60 ± 3*
ATP	133 ± 19*‡	93 ± 1	143 ± 21*‡	54 ± 3
B. Dexmedetomidine trials
Baseline
Adenosine	27 ± 4	95 ± 2	28 ± 4	53 ± 3
Exercise	30 ± 6	92 ± 3	33 ± 7	54 ± 4
ATP	30 ± 6	97 ± 2	31 ± 6	54 ± 3
Pre-dexmedetomidine
Adenosine	141 ± 25*	98 ± 3	144 ± 25*	54 ± 4
Exercise	150 ± 16*	94 ± 2	158 ± 15*	57 ± 4*
ATP	153 ± 20*	95 ± 2	162 ± 21*	54 ± 3
Dexmedetomidine
Adenosine	85 ± 15*†	101 ± 3	84 ± 15*†	55 ± 3
Exercise	132 ± 12*†‡	95 ± 2	136 ± 12*†‡	57 ± 4*
ATP	152 ± 23*‡	96 ± 2	159 ± 24*‡	53 ± 3

^*P< 0.05 vs baseline within condition;

^†P< 0.05 vs steady-state (Pre-vasoconstrictor; Phenylephrine/Dexmedetomidine) within condition;

^‡P< 0.05 vs adenosine during α-agonist infusion. Forearm vascular conductance was calculated as (forearm blood flow/mean arterial pressure) × 100.