Fig. 3

Increases in diastolic blood pressure produced by i.v. dyhydroergotamine (1–3100 μg/kg) after i.v. treatment with 1% ascorbic acid (△, 1 ml/kg); 100 μg/kg ritanserin (☐); or 100 μg/kg ritanserin followed by 1 ml/kg saline (◇) (n = 5 each). Empty symbols depict either control responses in untreated animals (○) or non-significant (P > 0.05) responses (△, ☐,◇) versus the control group (○). Solid symbols (■,◆) represent significantly different responses (P < 0.05) versus the control group (○) or versus the group pretreated with 1% ascorbic acid (△). Data are shown as means ± SEM. Δ Diastolic blood pressure stands for “increases in diastolic blood pressure”