Figure 6.

Effects of physostigmine and electrical field stimulation (EFS) (10 Hz) on 5 day cultured dorso-medial and lateral muscle strips in the guinea pig bladder. In contrast to high KCl, physostigmine (1 µmol·L⁻¹) and EFS (10 Hz) evoked significantly smaller contractile responses in dorso-medial strips (A) than in lateral strips after 5 days in culture (B). An application of 80 mmol·L⁻¹ KCl is shown by arrowhead in (A) and (B). In (A), arrows show spontaneous contractions while filled dots mark EFS-induced contractions (in A and B). (C and D) Averaged data of the effects of physostigmine (1 µmol·L⁻¹) in fresh and 5 day cultured strips from dorso-medial (C) and lateral (D) regions of the bladder. Note that the effects of physostigmine in (A–D) are in the presence of tetrodotoxin (1 µmol·L⁻¹). Each value in (C) and (D) is the mean from four to seven guinea pigs. *, significant difference from fresh control tissue, P < 0.05.