TABLE 2

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

Compound
Level
Clearance
Spillover
Half-Time
nmol/L l/min nmol/min min
Noradrenergic
    VMA 30.0 0.6 21.0 32.0
    MHPG-S 23.0 0.3* 7.4*
    MHPG 20.0 1.3 25.0 28.0
    DHPG-S 6.6 0.3* 1.7*
    NMN-S 6.6 0.1* 0.7* >60.0
    DHPG 4.7 2.4 12.0
    NE-S 3.4 0.1* 0.5*
    Norepinephrine 1.0 1.7 2.6 2.0
    NMN 0.3 1.4 0.4 <4.0
Adrenergic
    MN-S 3.9 0.1* 0.5* >60.0
    Epinephrine-S 0.5 0.2* 0.1*
    MN 0.3 1.4 0.5 <4.0
    Epinephrine 0.2 2.3 0.5 ∼3.0
Dopaminergic
    HVA 70.0 0.8 63.0 40.0
    DA-S 9.7 0.1* 1.3 148.0
    DOPAC 8.9 0.5* >4.1*
    3-M-tyramine-S 2.8 0.12* 0.3* >60.0
    DA 0.1 2.8** 0.3 ∼2.0
    3-M-tyramine 0.03 0.5 0.02
DOPA
    3-M-tyrosine 87.0 0.005 0.4
    DOPA 8.9 0.9 7.4
    3-M-tyrosine-S 2.8 0.1 0.3 >60.0
    DOPA-S
2.1

  • ↵* Calculation based on renal removal or urinary excretion and therefore may underestimate total body clearance and spillover.

  • ↵** Calculation based on one-half of the published clearance from antecubital venous plasma.