Effect of dopamine and dopamine-antagonist infusion on blood platelet count, size and release reaction in hypertensive and normotensive subjects.
To examine the effect of dopamine on in vivo platelet function and a possible platelet contribution to the clearance of dopamine we measured platelet count, platelet size and plasma concentration of the platelet specific protein beta-thromboglobulin (BTG) in groups of 40 year old untreated hypertensive and normotensive men. One hypertensive (n = 10) and one normotensive (n = 10) group received dopamine infusion at doses from 0.5 to 2.0 micrograms/kg/min which increased plasma dopamine 100-fold from baseline. Two other groups of hypertensive (n = 10) and normotensive (n = 11) subjects received 10 mg of the dopamine antagonist metoclopramide intravenously, upon which serum prolactin concentration increased 10-fold. No significant effect on platelet function in any group was observed during these interventions. Platelet phenol-sulphotransferase may contribute to dopamine conjugation. However, the selected platelet parameters correlated only weakly with dopamine kinetics during the infusion. Neither dopamine nor a dopamine antagonist altered the selected platelet parameters, nor did these parameters influence the clearance of dopamine during a short-lasting pharmacological infusion.
Lande
K
K
Department of Internal Medicine, Oslo University Medical School, Ullevaal Hospital, Norway.
Os
I
I
Kjeldsen
S E
SE
Westheim
A
A
Hjermann
I
I
Eide
I
I
Gjesdal
K
K
D001792:Blood Platelets / Q000187:drug effects*; D004298:Dopamine / Q000008:administration & dosage* / Q000097:blood; D006801:Humans; D006973:Hypertension / Q000097:blood*; D007262:Infusions, Intravenous; D008297:Male; D008787:Metoclopramide / Q000008:administration & dosage*; D010976:Platelet Count / Q000187:drug effects; D011388:Prolactin / Q000097:blood; D011954:Receptors, Dopamine / Q000187:drug effects; D001620:beta-Thromboglobulin / Q000032:analysis
D011954:Receptors, Dopamine; D001620:beta-Thromboglobulin; D011388:Prolactin; D008787:Metoclopramide; D004298:Dopamine