RESUMO
Ten Sprague-Dawley male rats were sensitised with ovalbumin. The effect of hydrogen peroxide on the constrictor effect of acetylcholine was studied in the isolated tracheal muscle. Preincubation with hydrogen peroxide (H2O2) 10(-3) M (1 min/30 min) does not modify the acetylcholine constrictor effect in the control group. Ovalbumin sensitisation enhanced the acetylcholine constrictor effect (mean value of 19%) irrespective of dosage, comparatively with the control group. Short- and long-term preincubation with hydrogen peroxide enhanced the acetylcholine effect in the sensitised group, irrespective of dosage, comparatively with the control group. A relationship between dosage, contractile response and time of incubation was noticed only in the sensitised group.
Assuntos
Acetilcolina/farmacologia , Peróxido de Hidrogênio/farmacologia , Traqueia/efeitos dos fármacos , Vasoconstritores/farmacologia , Animais , Sinergismo Farmacológico , Imunização , Masculino , Músculo Liso/efeitos dos fármacos , Músculo Liso/imunologia , Ovalbumina/imunologia , Ratos , Ratos Sprague-Dawley , Valores de Referência , Fatores de Tempo , Traqueia/imunologiaRESUMO
The aim of this study was the investigation of bronchial reactivity in human bronchial smooth muscle in vitro. In fact, the study has two purposes: to achieve the best methods of research on human bronchial strips reactivity in vitro; to reveal the effect of acetylcholine and histamine on bronchial smooth muscle; The contractile effect of acetylcholine appears at 10(-6) M in the organ-bath; the maximal acetylcholine contraction was obtained at 10(-3) M in the organ-bath. Histamine induced a maximal contraction at 10(-3) M, but a concentration of 10(-3) M in the organ bath had no effect.
