Estudo anatomo-comparativo da fixação por formaldeido, álcool e solução salina saturada do tecido cerebral de ratos wistars

Abstract

Over the centuries anatomists have struggled to find a conservation technique that preserves the cadaver by preventing decomposition using chemicals that maintain it so that the corpse resembles living tissue and reduces the health-related risks of working with corpses. Formaldehyde is the most widely used fixative due to its ample availability, but it promotes darkening and weight gain beside is considered carcinogenic. Ethyl alcohol has been shown to be a potential substitute because it has effective tissue penetration preventing the proliferation of microorganisms, however it can only be used in isolation for fixation of small parts. In view of the limitations of these fixatives, saturated saline solution has been widely employed for its antimicrobial effect and its ability to maintain tissue similar to the original, furthermore hazardous effects are not generated as there is no evaporation of harmful substances. For this study we used 15 adult wistar rats (Rattus norvegicus), with an average body weight of 390g. After removal, the brains were submerged in 10 ml of the intended solution for 4 weeks. The weight of brains fixed in saturated saline did not change over the weeks. However, an increase in the weight of formaldehyde-fixed brains and a weight decrease in alcohol-fixed brains was observed, beside the modifications in the measures for all solutions. Thus, since the alterations observed was similar in all conservations, both saturated saline and alcohol proved to be efficient alternatives to the replacement of formaldehyde for fixation of brain tissue.