Table 2.

Plasma levels, clearances, spillovers, and half-times of catechols and their metabolites

Compound	Level (nmol/L)	Clearance (L/min)	Spillover (nmol/min)	Half-time (min)	References
Noradrenergic
VMA	30	0.6	21	32	Märdh et al. ([95], 1983), Kopin [85]
MHPG-S	23	0.3a	7.4a		Eisenhofer et al. [19]
MHPG	20	1.3	25	28	Märdh et al. (1983), Eisenhofer et al. [19]
DHPG-S	6.6	0.3a	1.7a		Eisenhofer et al. [19]
NMN-S	6.6	0.1a	0.7a	>60	Eisenhofer et al. [19]
DHPG	4.7	2.4	12		Eisenhofer et al. [29]
					Goldstein et al. [41]
NE-S	3.4	0.1a	0.5a		Goldstein et al. [63]
Norepinephrine	1.0	1.7	2.6	2	Kopin et al. [86], Goldstein et al. [41, 59], Eisenhofer et al. [19]
NMN	0.3	1.4	0.4	<4	Eisenhofer et al. [23]
Adrenergic
MN-S	3.9	0.1a	0.5a	>60	Eisenhofer et al. [19]
Epinephrine-S	0.5	0.2a	0.1a		Goldstein et al. [63], Eisenhofer et al. [19]
MN	0.3	1.4	0.5	<4	Eisenhofer et al. [23]
Epinephrine	0.2	2.3	0.5	~3	Eisenhofer et al. [32] Goldstein et al. [60]
Dopaminergic
HVA	70	0.8	63	40	Elchisak et al. [33], Kopin [85]
DA-S	9.7	0.1a	1.3	148	Eisenhofer et al. [18], Goldstein et al. [63]
DOPAC	8.9	0.5a	>4.1a		Eisenhofer et al. [29]
3-MTyramine-S	2.8	0.12a	0.3a	>60	Eisenhofer et al. [18]
DA	0.1	2.8b	0.3	~2	Goldstein et al. [63], Levinson et al. [93]
3-MTyramine	0.03	0.5	0.02		Buu et al. [12], Eisenhofer et al. [18]
DOPA
3-MTyrosine	87	0.005	0.4		Ishimitsu and Hirose [74], Armando et al. (1991),    Eisenhofer et al. [25]
DOPA	8.9	0.9	7.4		Wolfovitz et al. [130], Armando et al. (1991),    Goldstein et al. [41]
3-MTyrosine-S	2.8	0.1	0.3	>60	Eisenhofer et al. [18]
DOPA-S	2.1				Goldstein et al. [63]

^aCalculation based on renal removal or urinary excretion and therefore may underestimate total body clearance and spillover

^bCalculation based on one-half the published clearance from antecubital venous plasma