Analysis of biological materials by the atomic absorption spectrophotometry. I. Determination of total copper, iron and zinc in chicken livers

São apresentados os resultados obtidos na determinação do cobre, ferro e zinco, em fígado seco de frangos de corte da linhagem Shaver-Starbro, utilizando a espectrofotometria de absorção atômica como método analítico. Também são analisadas as possibilidades de estudo do metabolismo destes elementos em aves, sendo indicados alguns campos de estudo do metabolismo mineral em que as aves se prestam admiravelmente à experimentação. Os valores encontrados nos fígados analisados (expressos em ppm no tecido seco), foram 14,4 ± 0,85 ppm para o cobre; 283,3 ± 19,78 ppm para o ferro e 130,4 ± 4,21 ppm para o zinco. Estes valores estão dentro dos limites indicados na escassa literatura existente a respeito. O método utilizado foi controlado para a verificação da ocorrência de interferências, de perdas, contaminação operacional e reprodutibilidade analítica, pelas provas do erro de duplicatas e de recuperação dos três elementos, na presença e na ausência de matéria orgânica. Tais provas forneceram resultados significativos, sendo que a recuperação dos três elementos na ausência de matéria orgânica foi de 101,3% para o cobre, 102,9% para o ferro e 99,0% para o zinco; na presença de matéria orgânica os resultados foram: 92,9%, 97,7% e 98,0%, respectivamente. Não foi verificado ocorrerem interferências por parte de outros elementos presentes na cinza em grande quantidade, como o sódio, o potássio, o cálcio e o fósforo. A prova do erro de duplicatas indicou grande uniformidade dos resultados obtidos. A análise dos elementos presentes em tecidos e líquidos biológicos por absorção atômica se recomenda pela versatilidade, sensibilidade e comodidade para o manuseio de grande número de amostras e, principalmente, pela eliminação dos métodos de fracionamento dos componentes da mistura.Total copper, iron and zinc contents of male Shaver-Starbro pullet chicken livers were determined by atomic absorption spectrophotometry. In applying this method to dry ashed samples of liver tissue from 32 normal animals (1,34 mean body weight) the following values were obtained: 14,4 ± 0,85 for copper, 283,3 ± 19,78 for iron and 130,4 ± 4,21 for zinc (mean ± standard deviation ppm refered to tissue dry weight). Recovery tests were carried out to check the occurrence of metal interferences and contamination as well as analytical losses. Very good recoveries were obtained both in the absence of organic matter (101,3% for Cu, 102,9% for Fe and 99,0% for Zn) and in the presence of chicken powder (92,9% for Cu, 97,7% for Fe and 98,0% por Zn). The results of these tests excluded the eventual contamination of the samples, glassware and reagents used. There were no evidences of any spectral interference by other elements normally present in large amounts in the ashes, such as, sodium, potassium, calcium and phosphorus. Duplicate error of analysis indicated the good reproducibility of the method. Atomic absorption spectrophotometry quantitative analysis of the metalic elements occurring in animal tissues and body fluids is recommended in view of its sensitivity, versatility and convenience. The advantages have been emphasized particularly for surveys on trace elements deficiences occurring in bovine and other animal species, which requires a convenient handling of large number of samples. The method offers, even so, the advantage of a direct analytical tool, free of troublesome and time consuming fractionation steps. The simplicity of the procedure and the reproducibility and reliability of the results obtained lead to the adaption of this method for analytical studies of bovine and avian mineral metabolism undertaken in this laboratory

Influência do propianato de testosterona e do "Diffusing factor" sôbre a cicatrização cutânea de lesões experimentais

<abstract language="eng">The effect of testosterone propionate in different treatments was tested in adult male rats (250 g.) with mechanical skin experimental lesions. The whole period of cicatrization was investigated in normals, castrated and testosterone treated animals. We could not detect any alteration in the regeneration process in both treated and untreated rats (normals and castrated). Diffusing factor obtained from homologous testis, directly applied upon the lesions also do not change the healing period. Related to the course of the healing process, little evidence is presented by variance analysis that significative differences could be detected in the first periods, in both castrated and testosterone treated groups; however new well planed experiments should be carried to test this point

Estudos sobre a regeneração do figado - variação do volume nuclear das celulas hepáticas em repouso divisional

<abstract language="eng">Surgical removal of large amounts of hepatic tissue in male albino rats results in a rapid and conspicuous raise in cellular nuclear volumes. Measurements were made exclusively in resting nuclei. This volume variation is transitory. Nuclear volumes return to the normal value withins 6 days of restoration. The higher value are abserved 48 hours after the hepatic removal, indicating probably that this effect is due to hydration of the nucei, as occurs in the cytoplasm. This hydration could be correlated to the mitotic activity of the renmant tissue since a peak of mitoses parallels the changes in the nuclear volumes