Vol. 291, Issue 2, 642-647, November 1999

Beneficial Effects of Ropivacaine in Rat Experimental Colitis¹

Titti Martinsson, Tryggve Ljung, Carlos Rubio and Per M. Hellström

Discovery Division, Astra Pain Control, Huddinge, Sweden (T.M.); Department of Medicine, Gastroenterology Unit, Karolinska Hospital, Stockholm, Sweden (T.L., P.M.H.); and Department of Pathology and Cytology, Karolinska Hospital, Stockholm, Sweden (C.R.)

Ropivacaine, a new, long-acting local anesthetic agent, has been shown to have beneficial effects in the treatment of ulcerative colitis. Treatment with this drug results in prompt symptomatic relief. The aim of this study was to examine the effects of ropivacaine on mucosal healing and to investigate whether ropivacaine can restore the decreased colonic contractility seen in the diseased state. Colitis was induced in rats by a single intrarectal administration of trinitrobenzene sulfonic acid. Mucosal healing was assessed after 1 week of therapy. The effects on colonic contractility were examined either after 1 week of treatment or by application of the drugs to untreated, inflamed rat colon segments placed in organ baths. After the induction of colitis, daily intracolonic treatment with ropivacaine for 1 week reduced morphological damage and myeloperoxidase activity. One week of treatment also restored the contractile response to acetylcholine. By adding ropivacaine directly to untreated inflamed colonic segments in organ baths, the contractile response to acetylcholine was increased compared with controls. For comparison, the effects of budesonide and 5-aminosalicylic acid were also examined. Ropivacaine improved mucosal healing and restored colonic motor activity in experimental colitis, similar to budesonide but superior to 5-aminosalicylic acid.