Fig. 5. The effects of (Aii) cVIP (10^–6 mol l^–1; N=15), (Bii) Ang II (10^–5 mol l^–1; N=6) and (Cii) methylcholine (10^–3 mol l^–1; N=6) on catecholamine secretion rates (Ai–Ci) in posterior cardinal vein preparations previously perfused with control saline (hatched bars) or after rapidly switching to saline containing nicotine (10^–5 mol l^–1; filled bars). An asterisk denotes a statistically significant difference from the `preswitch' (Pre) value; a dagger represents a significant difference from the secretion rate after 10 min; a double dagger represents a significant difference from the control (saline-perfused) group. Agonist inj. indicates rate measured after agonist injection (see Materials and methods).