Phenylpyrazolone derivatives inhibit gastric emptying in rats by a capsaicin-sensitive afferent pathway.
Dipyrone (Dp), 4-aminoantipyrine (AA) and antipyrine (At) administered iv and Dp administered icv delay gastric emptying (GE) in rats. The participation of capsaicin (Cps)-sensitive afferent fibers in this phenomenon was evaluated. Male Wistar rats were pretreated sc with Cps (50 mg/kg) or vehicle between the first and second day of life and both groups were submitted to the eye-wiping test. GE was determined in these animals at the age of 8/9 weeks (weight: 200-300 g). Ten minutes before the study, the animals of both groups were treated iv with Dp, AA or At (240 micromol/kg), or saline; or treated icv with Dp (4 micromol/animal) or saline. GE was determined 10 min after treatment by measuring % gastric retention (GR) of saline labeled with phenol red 10 min after orogastric administration. Percent GR (mean +/- SEM, N = 8) in animals pretreated with Cps and treated with Dp, AA or At (35.8 +/- 3.2, 35.4 +/- 2.2, and 35.6 +/- 2%, respectively) did not differ from the GR of saline-treated animals pretreated with vehicle (36.8 +/- 2.8%) and was significantly lower than in animals pretreated with vehicle and treated with the drugs (52.1 +/- 2.8, 66.2 +/- 4, and 55.8 +/- 3%, respectively). The effect of icv administration of Dp (N = 6) was not modified by pretreatment with Cps (63.3 +/- 5.7%) compared to Dp-treated animals pretreated with vehicle (62.3 +/- 2.4%). The results suggest the participation of capsaicin-sensitive afferent fibers in the delayed GE induced by iv administration of Dp, AA and At, but not of icv Dp.
Vinagre
A M
AM
Departamento de Pediatria, Universidade Estadual de Campinas, Campinas, SP, Brasil.
Collares
E F
EF
D000344:Afferent Pathways / Q000187:drug effects*; D000675:Ampyrone / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000494:pharmacology*; D000983:Antipyrine / Q000008:administration & dosage / Q000494:pharmacology*; D002211:Capsaicin; D004177:Dipyrone / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005746:Gastric Emptying / Q000187:drug effects; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000675:Ampyrone; D004177:Dipyrone; D002211:Capsaicin; D000983:Antipyrine