The antiinflammatory effect of amniotic fluid on the lungs of rats inoculated intra-tracheally with silica. / Efecto antiinflamatorio del líquido amniótico en el pulmón de ratas inoculadas intratraquealmente con sílice

38 Wistar rats with a mean weight of 177 g were divided in 5 groups. Rats were inoculated i.t. with 0.5 ml of fluid (made up to a constant volume using saline solution) containing 2.5 mg of silica, but a variable amount of amniotic fluid (0, 0.125, 0.250, 0.375 or 0.500 ml). The rats were killed 72 h later. The number of bronchoalveolar cells per ml and percentage of neutrophils and alveolar macrophages determined by bronchoalveolar lavage was used as a measurable indicator of pulmonary inflammation. Inoculation with amniotic fluid and silica induced a significant influx of nucleated cells and neutrophils in bronchoalveolar lavage fluid of inoculated animals when compared to the control. The increase of nucleated cells and neutrophils was related to the volume of amniotic fluid inoculated. It is concluded that the amniotic fluid did not induce any antiinflammatory effect in the lungs of rats inoculated with silica.