Figure 3. Myographic parameters of uterine contractility.

A, the concentrations required to achieve half-maximal response (EC₅₀) for oxytocin-induced contractions in non-pregnant animals (open bars; n = 10), animals at mid-late pregnancy (grey bars; n = 14), day 21/22 not in labour (stippled bars; n = 21) or in active labour (black bars; n = 9). B, the maximal responses (area under the curve for the concentration of oxytocin giving the maximal response) for the same animals as in panel A. C, the spontaneous contractile activity for the same animals as in panels A and B. For each panel, bars with unique superscripts are significantly different (ANOVA; P < 0.05) from bars without overlapping superscripts.