Avaliação dos efeitos tóxicos do cianeto e do tiocianato no período perinatal. Estudo em ratos / Evaluation of toxic effects of cyanide and thiocyanate during perinatal period. Study in rats

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The aim of the present study was to determinate the toxic effects of long-term exposure to KCN and KSCN in rats, during perinatal period. Initially, it was achieved the toxicokinetics study of the thiocyanate in female rats, in three different physiological states: estrogenic, gestation and lactation. These animals received, per os, in the drinking water or by gavage, the unique dose of 3.0 mg KCN/kg. The results showed significantly increased in the thiocyanate levels in the serum, milk and amniotic fluid, after the administration of the KCN. The toxicokinetics parameters were calculated based on these data. In a second part, female rats were distributed in 18 experimental and 3 control groups. The experimental groups were dosed with 1, 3 and 30 mg KCN/kg or 0.8; 2.4 and 24 mg KSCN/kg, daily, in the drinking water, from days 6 to 20 of gestation and euthanized on day 20 of gestation or on day 22 postpartum; or received from days 1 to 19 of lactation and euthanized on day 19 of lactation. At the end of each experiment, the animals were euthanized, in the appropriated period, as well as the fetuses and pups. The serum samples were obtained in order to determine the thiocyanate, glucose, cholesterol, urea, creatinine, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase levels as well as samples of the following organs for the histopathological study: central nervous system, kidney, pancreas, thyroid, liver, lung and spleen. Yet, the levels of thiocyanate were evaluated in the amniotic fluid and milk, from the mothers, as well as the skeletal and visceral analysis of the fetuses. From the biochemical parameters, in relation to the dams, it was verified that the thiocyanate levels were significantly increased, in several experimental groups; otherwise, too few alterations were observed in the enzymes and others substances analyzed. The histopathological study revealed, in the pregnant and lactating rats, nephrosis, hemorrhage and hemosiderosis in the kidneys; congestion, neuronophagia and gliosis in the CNS; vacuolization and proliferation of the biliar ducts in the liver and increase in the number of reabsorption vacuoles in follicular colloid, in a dose-dependent manner, in some experimental groups. At the pregnant rats that were euthanized on day 20 of gestation, it was verified depletion of cells from the islets of Langerhans. In relation to the pups, from mothers exposed during the gestation and lactation, it was verified alteration in the thiocyanate levels from experimental groups and the histopathological study revealed: congestion, neuronophagia and gliosis in the CNS, renal and hepatic congestion, vacuolization and proliferation of biliar ducts. On the other hand, it was verified no alterations in the reproductive performance nor skeletal and visceral analysis of the fetuses. Thus, it was suggested that the cyanide and/or its metabolite promoted toxic effect straight to the fetuses; however, these alterations are susceptible of detection only at postnatal phase. Furthermore, the cyanide and/or thiocyanate are transferred to the breast milk of rats and can also compromise the health of the offspring.

ASSUNTO(S)

amniotic fluid intoxicação ratos intoxication leite reproductive toxicology milk líquido amniótico rats toxicologia reprodutiva sangue blood

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