Ischemia-reperfusion injuryExperimental: IntestinalAtenolol to Treat Intestinal Ischemia and Reperfusion in Rats

To study whether treatment with the beta-blocker atenolol (AT) attenuates intestinal dysfunction caused by ischemia (I) and reperfusion (R), rats were treated with AT (1.5 mg · kg−1, intravenously) or saline solution (SS) prior to I (60 minutes), which was produced by occlusion of the superior mesenteric artery, and/or R (120 minutes). After I or I/R, 2-cm jejunal segments were mounted in an organ bath to study neurogenic contractions stimulated by electrical pulses or KCl using a digital recording system. Thin jejunal slices were stained with hematoxylin and eosin for optical microscopy analysis. Compared to the sham group, jejunal contractions were similar in the I + AT and the I/R + AT groups, but reduced in the I + SS and the I/R + SS groups. The jejunal enteric nerves were damaged in the I + SS and the I/R + SS groups, but not in the I + AT and the I/R + AT. These results suggest that AT may attenuate intestinal dysfunction caused by I and I/R.