Time course of alpha 2-adrenoceptor desensitization induced by adrenaline infusion in man.
After a rapid increase in infusion rate of adrenaline to elevate the initial heart rate by more than 15%, a continuous infusion was sustained in order to maintain elevated adrenaline plasma levels. At the end of the first phase of the experiment, the thrombocyte alpha 2-adrenoceptor number (determined by radioligand binding) was significantly lowered. After the second part of the experiment, a further significant decrease in the density of binding sites was observed, while elevated adrenaline plasma levels were kept constant. The decrease in the number of binding sites was accompanied by a slight increase in affinity of the radioligand. Serum potassium concentration significantly decreased during the experiment, while other serum electrolytes showed no significant alterations.
Lübbecke
F
F
Center of Internal Medicine, Justus Liebig University, Giessen, FRG.
Zschätzsch
S
S
Mitrovic
V
V
Husseini
H
H
Schütterle
G
G
Wizemann
V
V
D000328:Adult; D001665:Binding Sites / Q000187:drug effects; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D002395:Catecholamines / Q000097:blood; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004837:Epinephrine / Q000008:administration & dosage / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects; D011188:Potassium / Q000097:blood; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D015016:Yohimbine / Q000378:metabolism
D002395:Catecholamines; D011942:Receptors, Adrenergic, alpha; D015016:Yohimbine; D011188:Potassium; D004837:Epinephrine