Fig. 2. (A) Effect of PR (1 µmol l^-1, 90 s) on membrane potential (mV) and input resistance (uncalibrated, downward deflections, upper trace), and on tetani and contracture (lower trace). The resting membrane potential before PR was -68 mV. During the contracture there was a period of 2 min during which the OOM showed oscillations in membrane potential and force. (B) Effect of F₂ (1 µmol l^-1, 90 s) on membrane potential (mV) and input resistance (uncalibrated, downward deflections, upper trace), and on tetani and contracture (lower trace). The resting membrane potential before F₂ was -80 mV. During the contracture there were spontaneous contractions and fluctuations in membrane potential.