Figure 3. The effects of weak acids on myometrial contractions .

A, the effects of 5 mM sodium butyrate, propionate, lactate and pyruvate on spontaneously contacting rat myometrium; typical traces from three to six different preparations. B, typical traces (i) showing the effect of propionate application, from 1 to 20 mM, on spontaneously contracting myometrium; dose–response curves (ii) for AUC of spontaneous contractions in the presence of lactate (red) and propionate (green); and dose–response curves (iii) for AUC in the presence of oxytocin, for lactate (red) and propionate (green).