RESUMO
Catalase is an antioxidant enzyme that plays a very important role in the protection against oxidative damage by breaking down hydrogen peroxide. It is a very highly conserved enzyme that has been identified from numerous species including bacteria, fungi, plants and animals, but the information about catalase in crustaceans is very limited. A cDNA containing the complete coding sequence for catalase from the shrimp Penaeus (Litopenaeus) vannamei was sequenced and the mRNA was detected by RT-PCR in selected tissues. Catalase was detected in hepatopancreas crude extracts by Western blot analysis with anti-human catalase polyclonal antibodies. The nucleotide sequence is 1692 bp long, including a 72-bp 5'-UTR, a coding sequence of 1515 bp and a 104-bp 3'-UTR. The deduced amino acid sequence corresponds to 505 amino acids with high identity to invertebrate, vertebrate and even bacterial catalases and contains the catalytic residues His71, Asn144, and Tyr354. The predicted protein has a calculated molecular mass of 57 kDa; which coincides with the size of the subunit (approximately 55 kDa) and the tetrameric protein (approximately 230 kDa) detected in hepatopancreas extracts under native conditions. Catalase mRNA level was higher in hepatopancreas, followed by gills and was not detected in muscle.
Assuntos
Catalase/fisiologia , Regiões 3' não Traduzidas , Regiões 5' não Traduzidas , Sequência de Aminoácidos , Animais , Antioxidantes/química , Sequência de Bases , Western Blotting , Catalase/metabolismo , Clonagem Molecular , DNA Complementar/metabolismo , Eletroforese em Gel de Poliacrilamida , Hepatopâncreas/metabolismo , Humanos , Dados de Sequência Molecular , Penaeidae , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de AminoácidosRESUMO
Se expone un caso de síndrome de Bartter en un lactante menor de dos meses de edad con antecedente prenatal de polihidramnios y parto pretérmino. Con historia de vómito, diarrea y estreñimiento ocasional, asociado con retardo pondoestatural. Este paciente presentó cuadro de bronconeumonía viral la cual evolucionó en forma tórpida con aumento del síndrome de dificultad respiratoria (SDR) y deterioro del estado general por lo cual hubo necesidad de trasladarlo a la unidad de cuidado intensivo de pediatría. Allí se corroboró la presencia de alcalosis metabólica hipokalémica e hipoclorémica con aumento de la excreción urinaria de K, Na y Cl y defecto en la habilidad de concentrar la orina. Aunado a esto se detectó hiperreninemia, poliuria y aldosterona elevada. La tensión arterial fue normal con un percentil menor de cinco para el peso y de 10 para la talla. Con base en todo lo anterior se pudo confirmar el diagnóstico de síndrome de Bartter