Example of stress behavior.

<p>(<b>A</b>) Carprofen treated rat exhibiting distress reactions 1 h after surgery. (<b>B</b>) Carprofen+Tramadol treated rat showing normal behavior 1 h after surgery.</p

Pain assessment.

<p>Number of signs of pain during the first (<b>A</b>) and the second hour (<b>B</b>) after recovery from surgery. Horizontal lines represent mean values.</p

Left coronary artery ligation.

<p>(<b>A</b>) Heart visualization by the 15 mm opening of the 5^th intercostal space. (<b>B</b>) LAD was ligated with 4-0 silk suture and the plain knot was tied over two loops of suture. After 30′ ischemia loops were pulled and the knot was released allowing reperfusion.</p

Non-standard Abbreviations.

<p>Non-standard Abbreviations.</p