Figure 2. Mean data of contractile parameters of isometric (left) and isotonic (right) twitches of all muscles of protocol 1. 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). The filled squares and circles represent a statistically significant difference with respect to data at condition "EE." For the sake of clarity, bars representing SEM were omitted from the figures. With an intact EE, thiopental induced a dose-dependent decrease in parameters of isotonic and isometric twitch. In the muscles with EE removed, increasing doses of thiopental up to 6 micro gram/ml did not change isometric and isotonic twitch parameters.