Table 1.

Hemodynamic, sympathetic, and renal vascular responses to IFRHG during Visit 1.

						IFRHG	IFRHG
			Base 1	Base 2	CA	First 20	Peak	PHGCA	Infusion	Time	Interaction
MAP	mmHg	Saline	84 ± 2	87 ± 3	89 ± 3	94 ± 4	118 ± 4	110 ± 3	0.563	< 0.001	0.290
		Ascorbic Acid	85 ± 2	88 ± 3	92 ± 3	93 ± 3	117 ± 4	111 ± 4
HR	bpm	Saline	61 ± 2	62 ± 3	68 ± 2	71 ± 2	81 ± 3	65 ± 3	0.140	< .001	0.161
		Ascorbic Acid	60 ± 2	63 ± 2	69 ± 3	76 ± 3	83 ± 4	66 ± 2
MSNA	burst/min	Saline	21 ± 3	19 ± 2	16 ± 3	18 ± 3	40 ± 4	35 ± 3	0.793	< .001	0.928
		Ascorbic Acid	19 ± 3	20 ± 4	17 ± 3	19 ± 3	41 ± 4	35 ± 3
MSNA	total activity	Saline	351 ± 50	325 ± 48	256 ± 55	285 ± 53	1047 ± 134	897 ± 79	0.782	< 0.001	0.779
		Ascorbic Acid	331 ± 46	321 ± 57	310 ± 61	320 ± 67	1017 ± 123	860 ± 104
RBV	cm/sec	Saline	50.9 ± 4.2	52.1 ± 3.1	52.3 ± 3.7	54.2 ± 6.9	54.1 ± 7.0	51.7 ± 5.6	0.669	0.895	0.413
		Ascorbic Acid	54.9 ± 3.8	54.0 ± 5.0	52.2 ± 4.3	55.4 ± 5.0	52.7 ± 8.7	56.6 ± 5.4

Subjects (n=10) underwent resting baseline periods before (Base 1) and after (Base 2) infusion of normal sterile saline and then ascorbic acid. Circulatory arrest (CA, inflation of upper arm cuff to suprasystolic pressure) occurred for one minute prior to the onset of ischemic fatiguing rhythmic handgrip (IFRHG) exercise and the occlusion cuff remained inflated for two minutes of post-handgrip circulatory arrest (PHGCA). Measurements included beat-by-beat mean arterial pressure (MAP), heart rate (HR), muscle sympathetic nerve activity (MSNA), and renal blood flow velocity (RBV). Data are M ± SEM.