Assuntos
Gliceraldeído-3-Fosfato Desidrogenases/isolamento & purificação , Fígado/enzimologia , Sulfato de Amônio , Animais , Catálise , Fenômenos Químicos , Físico-Química , Cromatografia por Troca Iônica/métodos , Cristalização , Concentração de Íons de Hidrogênio , Espectrofotometria Ultravioleta/métodos , SuínosRESUMO
When chicken breast muscle was homogenized in water, approximately 86% of the glyceraldehyde-3-phosphate dehydrogenase was associated with the particulate fraction. The enzyme was solubilized by increasing pH with a very marked increase in the pH range of 6.9 to 7.1. At low ionic strength (about 0.015), approximately 50% of the enzyme is solubilized at pH 7.5 and above. Increasing ionic strength also led to increased solubilization. In addition, there was a specific cation effect with Ca2+ greater than Mg2+ greater than K+ greater than Na+ at a constant ionic strength. Glyceraldehyde 3-phosphate and 2,3-bisphosphoglycerate were effective in partially solubilizing the enzyme. Solubilized glyceraldehyde-3-phosphate dehydrogenase can rebind to the particulate fraction of the homogenized muscle. The soluble form of the enzyme has a higher V and a higher Km (glyceraldehyde-3-phosphate) than the enzyme bound to the particulate fraction.
Assuntos
Gliceraldeído-3-Fosfato Desidrogenases/análise , Músculos/enzimologia , Animais , Cátions Bivalentes , Cátions Monovalentes , Galinhas , Feminino , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Concentração Osmolar , Ligação Proteica , Solubilidade , Frações Subcelulares/enzimologiaRESUMO
Arak, the national alcoholic drink in Lebanon, was prepared from grapes to which either DDT or parathion had been added. Samples of the nine fractions produced from the fermentation and distillation steps were analyzed for DDT and parathion and their respective metabolites. DDT degraded to DDD during the fermentation step resulting in a sharp decrease in DDT level. The two distillation steps contributed to a further decrease in the DDT level so that the final product contained less than 2% of the amount found in the fresh grape juice. Although the concentration of DDD increased sharply during fermentation, it also decreased to a negligible level during the subsequent distillation procedure. Parathion was more stable than DDT during the fermentation and first distillation steps. However, the second distillation process caused a sharp decline in its level and the Arak contained only about 6% of the residues present in the fresh juice, paranithophenol being the only metabolite detected.
Assuntos
Bebidas Alcoólicas/análise , DDT/análise , Paration/análise , Cromatografia Gasosa , Cromatografia em Camada Fina , Diclorodifenildicloroetano/análise , Líbano , Nitrofenóis/análise , Resíduos de Praguicidas/análiseRESUMO
Studies have been conducted to determine the distribution of dieldrin in various tissues of rainbow trout when exposed to several dieldrin concentrations. Medium sized fish with an average weight and length of 195.4 +/- 30.5 g and 25.7 +/- 1.4 cm, respectively, were placed in groups of 6 in 300 L tanks containing purified and aerated water and maintained at 10 degrees C. Following an acclimatization period of 10 days, each group of fish was exposed to one of four dieldrin concentrations ranging from 50 to 80 ppb. After 24 hours, the fish were taken out of the tanks and sacrificed. The brain, gills, liver, muscles and skin were collected from each fish. Dieldrin was extracted from each tissue using SPE techniques and analyzed by both gas chromatography (GC) and enzyme linked immunosorbent assay (ELISA). Results of analyses by the two techniques were highly correlated. The results also showed that liver and skin tissues had the highest level of dieldrin residues. In comparing the means of the six fish samples, it was found that liver or skin contained about 1.5-fold the level in brain, about 4.0 fold the level in muscles and about 6.5 fold the level in gills. Immunoassay proved to be as reliable an analytical tool as gas chromatography in this case.
Assuntos
Cromatografia Gasosa/métodos , Dieldrin/farmacocinética , Ensaio de Imunoadsorção Enzimática/métodos , Oncorhynchus mykiss/metabolismo , Resíduos de Praguicidas/análise , Animais , Encéfalo/metabolismo , Dieldrin/análise , Exposição Ambiental , Brânquias/química , Brânquias/metabolismo , Fígado/química , Fígado/metabolismo , Músculos/química , Músculos/metabolismo , Pele/química , Pele/metabolismo , Distribuição TecidualRESUMO
Wine and Arak, the national alcoholic drink in Lebanon, were prepared from grape juice fortified with fenitrothion to a concentration of 20ppm. Samples of the 11 fractions produced by the fermentation and distillation steps were analyzed for fenitrothion residues using gas chromatography (GC) and enzyme-linked immunosorbent assay (ELISA). Results of residue analyses showed that the two techniques were highly correlated (r = 0.978) and indicated that fenitrothion was stable during the fermentation steps but not during distillation. The clarified wine 35 days later contained about 85% (15.3 ppm) of the fenitrothion concentration found in the juice as determined by GC analysis. Arak was prepared by a two-steps distillation of the clarified wine. The alcohol distillate and undistilled fraction from the first distillation contained 2.5 ppm and 5.8 ppm of fenitrothion, respectively. No fenitrothion residues were detected by both techniques in the four fractions collected from the second distillation step.
Assuntos
Bebidas Alcoólicas/análise , Fenitrotion/análise , Inseticidas/análise , Cromatografia Gasosa , Imunoensaio , RosalesRESUMO
Milk samples were collected from 32 nursing mothers living in the Beirut area, Lebanon. Dietary intakes of participating mothers were obtained from data of their diet histories, 24 h dietary recalls and food frequency questionnaires. Milk samples were screened for the presence of organochlorine pesticide residues and DDE levels were estimated using gas chromatographic techniques. The relationship between consumption of various food groups and DDE content of milk was investigated. A positive correlation was found between the consumption of either/or high fat meat, tuna fish and DDE levels in milk. Consumption of poultry products showed a weak correlation with DDE content of milk, whereas consumption of vegetable oils showed a negative correlation.