RESUMO
The prophenoloxidase activating system plays a major role in the defense mechanism of arthropods. In the present study, the phenoloxidase activity and its location in the hemolymph of the spiny lobster Panulirus argus is presented. Phenoloxidase activity was observed in the hemocyte lysate supernatant (HLS) and plasma after their incubation with trypsin. Higher amounts of trypsin were required to activate the HLS prophenoloxidase, due to the presence of a trypsin inhibitor in this fraction. Activation of prophenoloxidase was found when HLS was incubated with calcium, with an optimal pH between 7.5 and 8. This spontaneous activity is due to the prophenoloxidase activating enzyme, a serine proteinase that activates the prophenoloxidase once calcium ions were available. SDS was able to induce phenoloxidase activity in plasma and hemocyte fractions. Prophenoloxidase from HLS occurs as an aggregate of 300kDa. Electrophoretic studies combining SDS-PAGE and native PAGE indicate that different proteins produced the phenoloxidase activity found in HLS and plasma. Thus, as in most crustaceans, Panulirus argus contains a prophenoloxidase activating system in its hemocyte, comprising at least the prophenoloxidase activating enzyme and the prophenoloxidase. Finally, it is suggested that phenoloxidase activity found in plasma is produced by hemocyanin.
Assuntos
Monofenol Mono-Oxigenase/metabolismo , Palinuridae/enzimologia , Animais , Inibidores Enzimáticos/farmacologia , Precursores Enzimáticos/antagonistas & inibidores , Precursores Enzimáticos/metabolismo , Hemócitos/enzimologia , Monofenol Mono-Oxigenase/sangue , Serina Endopeptidases/efeitos dos fármacos , Serina Endopeptidases/isolamento & purificação , Serina Endopeptidases/metabolismo , Fatores de Tempo , Tripsina/metabolismoRESUMO
The nutritional status of a group of patients with epidemic neuropathy (EN) was reevaluated after a one-year follow-up to observe the changes occurred and to assess their relationship with the individual clinical evolution. 71 patients (40 men and 31 women) were examined. 28 had optic epidemic neuropathy and 43 mixed epidemic neuropathy. Vitamins thiamine, niacin, A and E were determined and the values were compared with those of risk 21 days later. There was an improvement of these indicators after 21 days as a response to the treatment, and an increase one year later of the percentage of individuals deficient in or situated at the margin of thiamine and niacin, which reflects a nutritional unbalance without an apparent association with the clinical evolution that showed a trend towards the recovery of the patients. This disassociation between the clinics and the nutritional and vitamin status suggest that the pathogeny of the EN may be connected with non-nutritional factors. The deficiency found in the nutritional vitamin state could anticipate a worsening of the clinical picture and/or the appearance of clinical manifestations corresponding to deficiency diseases.