Fig. 3. The enterins inhibit the NdWFamide-evoked tonic contraction of the anterior aorta. (Ai) The NdWFamide evoked contraction. 10^-7 mol l^-1 NdWFamide was applied for 8 min as indicated, before washing out. (Aii) Effect of 10^-7 mol l^-1 ENk on the NdWFamide-evoked contraction. 10^-7 mol l^-1 ENk was co-applied with NdWFamide 5 min after the initial NdWFamide application. (Aiii) Effect of 10^-5 mol l^-1 ENk on the NdWFamide-evoked contraction. (B) The concentration—response relationships of the enterins. The effects of six enterins (ENa, ENe, ENk, ENl, ENpa, ENr) on the NdWFamide-evoked contraction were tested. Amplitude of the contraction at the end of the application of the enterin (b in inset) was normalized to the one just before the application of the enterin (a in inset). Values are means ± S.E.M. (N=3-5) plotted against concentration of enterins. Smooth lines are best-fits of the equation described in Materials and methods. r₂ and n were fixed to 100 and -1, respectively. r₁ and logx0 for each fitting were as follows, respectively: ENa, 50.7, -6.9; ENe, 30.8, -6.8; ENk, 28.1, -7.0; ENl, 45.7, -6.8; ENpa, 26.0, -7.2; ENr, 43.5, -6.8.