Figure 3. Mean data of contractile parameters of isometric (left) and isotonic (right) twitches of all muscles of protocol 2. On each panel, the two lines represent the dose-response curve for thiopental in the presence (squares, filled lines) of EE and after EE was removed (circles, dashed lines). After pretreatment with L-NAME, increasing doses of thiopental up to 6 micro gram/ml, did not alter parameters of contraction, not only in muscles without EE but also in muscles with intact EE.