Comparison of fractal dimension and Shannon entropy in myocytes from rats treated with histidine-tryptophan-glutamate and histidine-tryptophan cetoglutarate

Introducao: As solucoes que provocam parada cardiaca eletiva estao em constante evolucao, porem, o composto ideal ainda nao foi encontrado. Os autores comparam uma nova solucao cardioplegica com histidina-triptofano-glutamato (Grupo 2) com histidina-triptofano-cetoglutarato (Grupo 1) em modelo de coracao isolado de rato. Objetivo: Quantificar a dimensao fractal e entropia de Shannon em miocitos de rato submetidos a cardioplegia utilizando solucao histidina-triptofano com glutamato em modelo experimental, considerando-se os marcadores caspase, IL-8 e Ki-67. Metodos: Vinte ratos machos de raca Wistar foram anestesiados e heparinizados. O torax foi aberto, realizado cardiectomia e infundido 40 ml/Kg de solucao cardioplegica apropriada. Os coracoes foram mantidos por 2 horas na mesma solucao a 4oC e, apos esse periodo, colocados em aparato de Langendorff por 30 minutos com solucao de Ringer Locke. Foram feitas analises imunohistoquimicas para caspase, IL-8 e KI-67. Resultados: A dimensao fractal e a entropia de Shannon dos coracoes submetidos a parada cardiaca eletiva nos grupos 1 e 2 nao foram diferentes. Conclusao: A quantidade de informacoes avaliada pela entropia de Shannon e a distribuicao das mesmas (dada pela dimensao fractal) nas lâminas de coracao de rato submetidas a cardioplegia com solucao histidina-triptofano-acetoglutarato ou histidina-triptofano-glutamato nao foram diferentes, o que mostra que a solucao de histidina-triptofano-glutamato e tao boa quanto a histidina-triptofano-cetoglutarato na preservacao dos miocitos em modelo de coracao isolado de rato. . Introduction: Solutions that cause elective cardiac arrest are constantly evolving, but the ideal compound has not yet been found. The authors compare a new cardioplegic solution with histidine-tryptophan-glutamate (Group 2) and other one with histidine-tryptophan-cetoglutarate (Group 1) in a model of isolated rat heart. Objective: To quantify the fractal dimension and Shannon entropy in rat myocytes subjected to cardioplegia solution using histidine-tryptophan with glutamate in an experimental model, considering the caspase markers, IL-8 and KI-67. Methods: Twenty male Wistar rats were anesthetized and heparinized. The chest was opened, the heart was withdrawn and 40 ml/kg of cardioplegia (with histidine-tryptophan-cetoglutarate or histidine-tryptophan-glutamate solution) was infused. The hearts were kept for 2 hours at 4oC in the same solution, and thereafter placed in the Langendorff apparatus for 30 min with Ringer-Locke solution. Analyzes were performed for immunohistochemical caspase, IL-8 and KI-67. Results: The fractal dimension and Shannon entropy were not different between groups histidine-tryptophan-glutamate and histidine-tryptophan-acetoglutarate. Conclusion: The amount of information measured by Shannon entropy and the distribution thereof (given by fractal dimension) of the slices treated with histidine-tryptophan-cetoglutarate and histidine-tryptophan-glutamate were not different, showing that the histidine-tryptophan-glutamate solution is as good as histidine-tryptophan-acetoglutarate to preserve myocytes in isolated rat heart. .