Figure 3.

Concentration–response curves for 7-nor-subincanadine E (SEC, 0.2–600 µmol l⁻¹) in rabbit corpora cavernosa precontracted (a) with phenylephrine (PE, 10 µmol l^-1), alone or in the presence of atropine (ATR, 10 µmol l⁻¹), and (b) with a high-concentration potassium solution (K⁺, 60 mmol l⁻¹), alone or in the presence of the combination of guanethidine (GUA, 10 µmol l⁻¹) and phenylephrine (10 µmol l⁻¹). Data are presented as mean±s.e.m. (n=5) of the relaxation expressed as percentage of phenylephrine or high potassium concentration-induced contraction.