Effect of intravenous dopamine infusion on plasma concentrations of dopamine and dopamine sulfate in men, during and up to 18 h after infusion.
OBJECTIVE
We investigated whether sulfoconjugation contributes to the inactivation of intravenously infused dopamine (DA) in low concentrations with a predominant action on the kidney.


METHODS
Plasma DA and dopamine sulfate (DA-S) concentrations were determined during 4 h of intravenous infusion of DA (2 microg/kg/min) and up to 18 h after cessation of infusion. Twenty-seven healthy young subjects participated in the placebo controlled, randomised and double-blind study.


RESULTS
Intravenously administered DA was sulfoconjugated rapidly and to a great extent. After starting the infusion, DA levels rose within minutes and reached a steady state after 30-60 min. The steady-state levels averaged 151.3 +/- 8.2 nmol/l. DA-S levels also increased markedly with infusion from 16.7 +/- 9.9 nmol/l at the start of infusion up to 261.2 +/- 24.2 nmol/l at 30 min after cessation of infusion. Plasma DA concentrations after cessation of the infusion decreased rapidly with an initial half-life of elimination of 4.8 min. Concentrations of plasma DA-S declined with a half-life of 4.5 h. Persistent elevations of free and conjugated DA compared with pre-treatment levels were observed even 18 h after cessation. Heart rate and blood pressure remained unchanged both during DA and saline infusion.


CONCLUSIONS
Findings indicate that the sulfoconjugation pathway contributes markedly to the inactivation of intravenously infused DA and seems not to be saturable by DA infusion in low doses.
Onasch
A
A
Institute of Sports Medicine, Universitätsklinikum Benjamin Franklin, Free University Berlin, Clayallee 229, D-14195 Berlin, Germany.
Tanzeem
A
A
Isgro
F
F
Böning
D
D
Strobel
G
G
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D004298:Dopamine / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D013463:Sulfuric Acid Esters / Q000097:blood*; D013997:Time Factors
D013463:Sulfuric Acid Esters; D004298:Dopamine