Alpha adrenergic antagonism by cyclosporine.
Cyclosporine has been shown to exert antiadrenergic actions in previous studies from this laboratory. Interactions of CsA with the alpha-one and alpha-two receptor were studied in rabbits. Blood pressure studies revealed that CsA exerts a competitive, reversible antagonism against norepinephrine, epinephrine, and phenylephrine. Further studies of heart rate depression by clonidine also demonstrated that CsA antagonizes this action. In conclusion, cyclosporine appears to act as a nonspecific alpha antagonist.
Department of Pharmacology, Rush Medical College, Chicago, Illinois 60612.
G W
GW
Parkhurst
A V
AV
Prancan
B H
BH
Moon
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003524:Cyclosporins / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D010656:Phenylephrine / Q000494:pharmacology; D011817:Rabbits; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*
D000317:Adrenergic alpha-Antagonists; D003524:Cyclosporins; D011942:Receptors, Adrenergic, alpha; D010656:Phenylephrine