Mean arterial blood pressure (BP) in (a) the HMR1556 study where anaesthetized rabbits received phenylephrine and either E-4031 (1, 3, 10 nmol kg−1 min−1), HMR1556 (25, 75, 250 nmol kg−1 min−1) or the combination of both drugs, and in (b) the ATX study where anaesthetized rabbits received phenylephrine and either E-4031 (1, 3, 10 nmol kg−1 min−1), ATX-II (0.4, 1.2, 4.0 nmol kg−1) or the combination of both drugs. Values are expressed as mean±s.e.mean. *P<0.05 for the profile of all the values in the third cycle in the combination group compared to the other groups, General Linear Model with interaction. To aid clarity, symbols for the within group statistical analyses have been omitted. At baseline and at the mid-point of each cycle there were no significant differences among groups, one-way ANOVA. ATX-II, sea anemone toxin.