Prophylactic administration of L-arginine improves the intestinal barrier function after mesenteric ischaemia

Ischaemia/reperfusion (I/R) of the intestine causes mucosal injury associated with a high death rate in rats.

To investigate whether nitric oxide (NO) might be implicated in the recovery of the intestinal mucosa after ischaemic insult.

Wistar rats were subjected to mesenteric artery occlusion for 90 minutes. The animals were given either L-arginine, the substrate of NO synthase, or molsidomine, a NO donor. The controls received casein hydrolysate. The compounds were administered by gavage 19, 16, and 1.5 hours before ischaemia. Mucosal barrier permeability and cGMP content were determined 24 hours after ischaemia.

Survival after I/R was 50% in the control group. Animals treated with L-arginine or molsidomine exhibited a higher survival rate (70% and 83% respectively). Mucosal barrier permeability was decreased in rats receiving L-arginine or molsidomine compared with controls (4.0 (0.9) and 2.6 (0.6) v 11.2 (1.6) 14C-PEG pmol/segment, p < 0.05). Increased cGMP content was seen in the mucosa of the L-arginine group.

The findings suggest that pretreatment with L-arginine or molsidomine ameliorates survival after intestinal I/R and improves mucosal barrier function.