Fig. 5. Effect of various dihydropyridines and verapamil on muscle contraction. Velar strips were subjected to field stimulation at 0.2 Hz for 30 ms. Mean peak tension was registered on a digital pen recorder through a capacitative force transducer. Peak tension was normalised to that in the ASW control. The perifusion rate was set at 1.5 ml min^-1 and the temperature of the perifusate was 10–12 °C. Values are means ± S.E.M.