An intent of correlating clinical manifestations and ultrastructural lung changes in mice inoculated with Tityus discrepans (Buthidae) venom.

Investigation of the pathogenesis of human pulmonary damage caused by the toxic aggression by Tityus discrepans venom relies to a considerable extent upon the use of animal models. In this work, authors examine the correlation of clinical manifestations and changes in the organisation of cellular and subcellular pulmonary components in the murine model that probably resembles the damage found in envenomed humans. To evaluate lung subcellular response to Tityus discrepans venom, male C57/Bl adult mice were randomised into two groups: envenomed mice were intraperitoneally injected at a dose of 5 mg/Kg of weight and controls received saline solution. Lung samples were processed by electronic microscopy techniques and observed in a Hitachi-300. Ultrastructural findings in pulmonary tissue showed a partial denudation of its epithelial cells; the basal membrane was irregular and swollen. In the interstice there were fibroblasts with multiple cytoplasmatic projections and abundant extracellular material. Adjacent to the interstice bronchiolar areas with cells showing disperse nuclear chromatin were appreciated. There were losses of the intercellular unions and a clear separation among the cellular plasmatic membranes was observed. In conclusion, we suggest that some of the clinical manifestations of scorpion envenoming may be determined by ultrastructural lung damage produced by toxins present in this venom.