Figure 1. A typical 10 mM caffeine-induced tension transient showing the experimental procedure for a load-release cycle. Numbers 1–4 are solution artifacts. The uptake phase represents the presence of halothane in solutions 1–3, and the release phase represents the presence of halothane (0.1–3.0%) in solution 4 with or without 10 mM caffeine. Duration of immersion is 5 min for solutions 1 and 2, 15 min for solution 3, and for solution 4 until steady state of the tension transient is reached. Three cycles were sequentially performed: a control (10 mM caffeine with no halothane), a test (halothane in the uptake phase or halothane with or without caffeine in the release phase), and finally another control.