CUMULATIVE AND NONCUMULATIVE DOSE-RESPONSE CURVES TO NORADRENALINE ONTHE DORSAL HAND VEIN

Cumulative and noncumulative dose-response curves to noradrenaline wer e compared in the human dorsal hand vein (DHV), using the DHV complian ce technique. This technique involves recording changes in the diamete r of a superficial hand Vein at a constant congestion pressure. Twelve healthy male volunteers (20-45 years) participated in one experimenta l session. Five incremental doses of noradrenaline acid tartrate (0.33 -33.33 ng min(-1)) were infused twice in each subject: first with 5-mi n washout (5% dextrose saline) periods in between (''noncumulative dos e-response curve''), then without interspersed washout periods (''cumu lative dose-response curve''). Two-factor analysis of variance (dose o f noradrenaline x method of infusion) showed a significant effect of d ose (F = 101.53, df = 4,44, p < 0.0001); however, there was no signifi cant effect of method of infusion (F = 0.21, df = 1,11, p > 0.1), indi cating that cumulative and noncumulative applications of noradrenaline resulted in similar dose-response curves. Neither method of noradrena line application had any effect on systemic blood pressure and heart r ate. Construction of cumulative dose-response curves allows the study of the interactions of noradrenaline with a systemically taken antagon ist during a narrow time window and the construction of more than one dose-response curve within the same experimental session. (C) 1996 Els evier Science Inc.