EFFECTS OF SPASMOLYTIC AND OR NONSTEROIDAL ANTIINFLAMMATORY DRUGS ON MUSCLE HYPERALGESIA OF URETERAL ORIGIN IN RATS/

Rats with artificial calculosis of one ureter develop hyperalgesia in the ipsilateral oblique musculature as evidenced by decreased vocaliza tion threshold to electrical muscle stimulation lasting over a week. T he aim of the study was to evaluate the effect on this hyperalgesia of spasmolytic anticholinergic and/or non-steroidal antiinflammatory dru gs, common therapies for colic pain in humans. Rats implanted with a u nilateral ureteral stone were treated for 10 days with: (1) saline; (2 ) hyoscine-N-butylbromide (15 mg/kg/day i.p.); (3) ketoprofen (15 mg/k g/day); or (4) hyoscine-N-butylbromide + ketoprofen (15 + 15 mg/kg/day ). Oblique muscle vocalization thresholds were measured daily for 3 da ys before and 10 days after operation. Ipsilateral thresholds decrease d significantly after stone implantation on: (1) seven days (max. 32%) for saline; (2) one day (max. 20%) for hyoscine-N-butylbromide; (3) o ne day (max. 18%) for ketoprofen, but did not change significantly for hyoscine-N-butylbromide + ketoprofen. These results indicate a protec tive effect against muscle hyperalgesia of ureteral origin by spasmoly tic and antiinflammatory drugs, maximal when the two treatments are co mbined.