Specific alpha-adrenoceptor-mediated vasoconstriction in human veins and interaction with the calcium entry blockers nifedipine and diltiazem.
In order to characterize the pharmacological properties of post-junctional alpha-adrenoceptors, the vasoconstricting effects of the non-specific alpha-adrenoceptor agonist noradrenaline, of the specific alpha 1-adrenoceptor agonist phenylephrine and of the specific alpha 2-adrenoceptor agonist azepexole and the interaction with the calcium entry blockers nifedipine and diltiazem were studied in hand veins of eight healthy volunteers. Both subtypes of alpha-adrenoceptors could be demonstrated in human hand veins in vivo. The alpha 1-subtype seemed to prevail. Vasoconstriction induced by stimulation of either post-synaptic alpha 1- or alpha 2-adrenoceptors was reduced by the calcium entry blockers diltiazem and nifedipine.
Schulte
K L
KL
Department of Internal Medicine, Klinikum Steglitz, Freie Universität Berlin, Federal Republic of Germany.
Laber
E
E
Meyer-Sabellek
W A
WA
Distler
A
A
Gotzen
R
R
D000328:Adult; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004110:Diltiazem / Q000494:pharmacology; D004347:Drug Interactions; D006225:Hand / Q000098:blood supply; D006801:Humans; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology*; D012039:Regional Blood Flow / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects*; D014680:Veins / Q000187:drug effects*
D002121:Calcium Channel Blockers; D011942:Receptors, Adrenergic, alpha; D004110:Diltiazem; D009543:Nifedipine