PeroxidaÃÃo lipÃdica em pacientes esquistossomÃticos esplenectomizados da zona da mata e em ratos submetidos à Dieta BÃsica Regional (DBR)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

The aim of this study was to investigate the oxidative stress in plasma and erytrhocytes from schistossomiasis mansoni patients subjected to clinical and splenectomy treatment associated with auto-implantation of spleen tissue, as well as, in young rats fed with a Regional Basic Diet (RBD) which has been used in the sugarcane rural area of Pernambuco state. The blood samples were collected from healthy individuals and from patients after 12 h fasting. The lipid peroxidation was evaluated by measuring: a) plasma Thiobarbituric Acid Reactive Substances (TBARS) by using the reaction with thiobarbituric acid which was read at 535 nm; b) conjugated dienes which were extracted with dichloromethane/methanol (2:1, v/v) and read at 233 nm. In this study it was utilized Wistar rats aged 2-, 12-, 25- and 60-day-old which were fed with commercial or RBD diet during all life. The susceptibility to oxidative stress was determined in organs from rats in the presence of various concentrations of iron (Fe2+), an ion that induces the production of free radical. It was found significant difference (P<0.05) in erythrocytes conjugated dienes level from patients (584.5 Â 287.65) in comparison to the control group (271.72 Â 85.36). On the other hand, TBARS concentration in plasma from patients (8.31Â3.83) was increased by 10% in relation to control level (7.3 Â 2.35), but this rise was not significant. Furthermore, a positive orrelation between the levels of TBARS and conjugated dienes was found in both groups, patients (P <0.01, r = 0.62) and controls (P <0.05, r = 0.57). The results sugest that the erythrocyte from patients are more susceptible to oxidative damage. The oxidative stress in cortex, liver and kidney from rats aged 2-, 12-, 25-, and 60-day olds, fed with DBR, evaluated by TBARS production, show increase-dependent of Fe2+ concentration. In cortex and kidney from malnourished rats, with 2-day-old, there was a low significantly (P <0.01) response in TBARS production, in relation to increase in concentratons of Fe2+, in comparison to controls of same age. However, with the growth the malnourished animal the TBARS production increase and it was similar to the controls in 12- and 25-day olds. In old rats (60-day-old), the concentration of TBARS produced by cortex from malnourished group was higher than control in the absence and presence of Fe2+ (2.5 e 5.0 μM), but in kidney the levels were significantly (P <0.05) high only in the presence of Fe2+. In the liver, with exception from 25-day-old malnourished rats that had TBARS production significantly (P <0.05) high only in 10 and 20μM of Fe2+, all the malnourished animals show levels of TBARS significantly (P <0.05) higher than the control rats independent of the rat age and Fe2+ concentration. The results suggest that: a) the lipid peroxidation reactions in erythrocytes from patients is increased and this is a strong indicator of oxidative stress associated to physiopathology of the disease. b) under experimental conditions the RBD also promote oxidative stress which is indicated by the increase in the lipid peroxidation stimulated by Fe2+, in membranes of cortex, liver and kidney

ASSUNTO(S)

estresse oxidativo bioquimica dieta bÃsica regional (dbr)

ACESSO AO ARTIGO

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