Fig. 1
From: Effects of delta-opioid receptor agonist pretreatment on the cardiotoxicity of bupivacaine in rats
Timeline of the experiment. At the baseline, rats were infused with 2 ml·kg−1··min−1 normal saline, 30% lipid emulsion, 0.1, 1.0, or 5.0 mg/kg BW373U86, the agonist of delta-opioid receptor for 5 min. After waiting 1 min to change the syringe and the speed of the infusion pump, 0.5% bupivacaine 3.0 mg·kg−1··min−1 was started to infuse until asystole occurs