Efeitos da indução de hiperóxia no tecido pulmonar de ratos wistar

Abstract

The aim of this study was to evaluate the 100% oxygen concentration effects in Wistar rats’ lung tissue after 72 hours of exposition. Twelve male rats with mean weight 210±15,9g, 60 to 90 days of age was studied, at random distributed in two groups with 6 animals. Control group remained in adaption phase conditions, and Hyperoxic group was submitted to inhalation of 100% humidified oxygen concentration with 12 L/min continuous administration during 72 hours. After exposition, all animals presented compatible signals of acute respiratory failure (respiratory rate increase, cyanosis and hypocinetic state), three animals to made death progress before 24 hours exposition. Histological analysis revealed alveolar septa thickness mean of 0,38±0,1 bm in Control group, and 0,62±0,2 bm in Hyperoxic group. The mean values of AgNOR dots for the Control group was 1,0±0,4 dots, and in Hyperoxic group 1,8±0,4 dots (p=0,0022). Acute inflammation, chronic inflammation, alveolar edema, alveolar hemorrhage, alveolar epithelium denuded areas and atelectasis weren’t observed. After results analysis it was concluded that 100% oxygen concentration after 72 hour exposition can cause histological alterations compatible with inflammatory process beginning and cellular activity increase by oxidative aggressions, causing respiratory dysfunction in whole group and death in some animals submitted to hyperoxia.