Cumulative and noncumulative dose-response curves to noradrenaline on the dorsal hand vein.
Cumulative and noncumulative dose-response curves to noradrenaline were compared in the human dorsal hand vein (DHV), using the DHV compliance technique. This technique involves recording changes in the diameter of a superficial hand vein at a constant congestion pressure. Twelve healthy male volunteers (20-45 years) participated in one experimental session. Five incremental doses of noradrenaline acid tartrate (0.33-33.33 ng min-1) were infused twice in each subject: first with 5-min washout (5% dextrose saline) periods in between ("noncumulative dose-response curve"), then without interspersed washout periods ("cumulative dose-response curve"). Two-factor analysis of variance (dose of noradrenaline x method of infusion) showed a significant effect of dose (F = 101.53, df = 4.44, p < 0.0001); however, there was no significant effect of method of infusion (F = 0.21, df = 1,11, p > 0.1), indicating that cumulative and noncumulative applications of noradrenaline resulted in similar dose-response curves. Neither method of noradrenaline application had any effect on systemic blood pressure and heart rate. Construction of cumulative dose-response curves allows the study of the interactions of noradrenaline with a systemically taken antagonist during a narrow time window and the construction of more than one dose-response curve within the same experimental session.
Department of Psychiatry, University of Nottingham, Queen's Medical Centre, England, U.K.
A H
AH
Abdelmawla
R W
RW
Langley
E
E
Szabadi
C M
CM
Bradshaw
D000328:Adult; D000704:Analysis of Variance; D004305:Dose-Response Relationship, Drug; D006225:Hand / Q000098:blood supply*; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000008:administration & dosage / Q000494:pharmacology*; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000494:pharmacology*; D014680:Veins / Q000187:drug effects / Q000378:metabolism / Q000502:physiology
D014662:Vasoconstrictor Agents; D009638:Norepinephrine