Orientador: Urbano M. F. MeirellesDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Não informadoAbstract: The acute edemagenic effect of four polysorbates (20, 40, 60, and 80) was studied in Wistar rats, after subcutaneous injections in the sole of the hindlimbs. These substances induced a similar pattern of paw edema, that was throughly followed by pletismographic measurements during 7 hours, and eventually 48 hours. At the standardized experimental conditions, the highest used concentrations of the polysorbates induce about 600 to 900 microlitres of increased paw volume, the maximum being collected after approximately 90 minutes, although about 70% of this could be already recorded 30 minutes from the injections. The edemas are strongly inhibited by dexametasone and by the 'H IND. 1¿-histamine receptor antagonist terfenadine, but are little or not sensitive to inhibition by the nonsteroid anti-inflammatory agents indomethacin or aspirin. The polysorbates exhibit the phenomenon of counter irritation, that is; a high degree of inhibition of the edema volume can be observed when one of these substances is simultaneously injected in both hindpaws of the same animal. No quantitative correlation could be found out between the edemagenic responses to the polysorbates and the viscosity or the tensoactivity of the injected solutionsMestradoMestre em Biologia Celular e Estrutural