Metabolic and calorigenic effects of dopexamine in healthy volunteers.
OBJECTIVE
To evaluate metabolic and calorigenic effects of dopexamine in healthy volunteers.


METHODS
Prospective, randomized trial.


METHODS
Laboratory of the University Department of Anesthesiology.


METHODS
Eight volunteers.


METHODS
After a control period, dopexamine was administered using four infusion rates (0.75, 1.5, 3.0, and 6.0 microg/kg/min).


RESULTS
Blood pressure, heart rate, oxygen consumption (VO2), and the plasma concentration of potassium, glucose, lactate, and norepinephrine were measured. Typical hemodynamic responses were seen. VO2 increased from 122 +/- 11 (SD) to 150 +/- 9 mL/min/m2 during the highest dopexamine infusion rate. Plasma potassium concentration decreased only during the highest infusion rate. Plasma glucose concentration increased during infusion rates of 3 and 6 microg/kg/min of dopexamine, from 90 +/- 5 to 99 +/- 5 mg/dL (5.0 +/- 0.3 to 5.5 +/- 0.3 mmol/L), and from 87 +/- 7 to 103 +/- 11 mg/dL (4.8 +/- 0.4 to 5.7 +/- 0.6 mmol/L), respectively. Lactate did not increase during dopexamine infusion. Plasma norepinephrine concentration increased during all four infusion rates.


CONCLUSIONS
It was not possible to differentiate the adrenergic receptor subtype responsible for the calorigenic and metabolic effects, since the putative beta2 adrenergic-receptor agonist, dopexamine, caused an increase in the plasma concentration of the beta1 adrenergic-receptor agonist, norepinephrine. Since beta2 adrenergic receptor-mediated effects such as hypokalemia were found only at infusion rates > or = 3 microg/kg/min, the effects of dopexamine at infusion rates < 3 microg/kg/min may be mainly mediated by stimulation of dopaminergic receptors and the indirect sympathomimetic action.
Geisser
W
W
Universitätsklinik für Anästhesiologie, Universität Ulm, Germany.
Träger
K
K
Hähn
A
A
Georgieff
M
M
Ensinger
H
H
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000328:Adult; D001786:Blood Glucose / Q000187:drug effects*; D004298:Dopamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology*; D016903:Drug Monitoring; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D019344:Lactic Acid / Q000097:blood; D016014:Linear Models; D008297:Male; D009638:Norepinephrine / Q000097:blood; D010101:Oxygen Consumption / Q000187:drug effects*; D011188:Potassium / Q000097:blood; D011446:Prospective Studies
D000318:Adrenergic beta-Agonists; D001786:Blood Glucose; D018491:Dopamine Agonists; D019344:Lactic Acid; C046318:dopexamine; D011188:Potassium; D004298:Dopamine; D009638:Norepinephrine