Effect of nabumetone treatment on vascular responses of the thoracic aortain rat experimental arthritis

Nabumetone is a nonsteroidal anti-inflammatory (NSAI) drug which is known t o cause less gastrointestinal damage than other NSAI drugs. This study was performed to evaluate whether nabumetone treatment might alter the vascular aberrations related to inflammation in a rat model of adjuvant-induced art hritis. Nabumetone treatment (120 or 240 mg.kg(-1).day(-1), orally) was ini tiated on the 15th day of adjuvant inoculation and continued for 14 days. A rthritic lesions, vascular contractile and relaxant responses and gastroduo denal histopathological preparations were evaluated 29 days after adjuvant inoculation. The contractile responses of aortic rings to phenylephrine and KCl were increased in grade 2 arthritic rats. In grade 3 arthritis only th e phenylephrine contractility was decreased. The relaxant responses to acet ylcholine and sodium nitroprusside were decreased in grades 2 and 3. In hea lthy rats, nabumetone did not change the vascular responses. After treatmen t of arthritic rats with nabumetone, both the contractile and relaxant resp onse of the aortic rings returned to normal, and arthritic score and paw sw elling were reduced. Gastroduodenal histopathology did not show erosions or ulcers in any of the groups. in conclusion, nabumetone improved the system ic signs and vascular alterations in experimental arthritis without showing any gastrointestinal side effects. Copyright (C) 2000 S. Karger AG, Basel.