Toxicity of cyanide in swine: evaluation of perinatal effects / Toxicidade do cianeto em suínos. Avaliação dos efeitos perinatais

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Cyanide and cyanogenic compounds are ubiquitous in nature and widely studied in toxicology. Long-term cyanide exposure has been associated to development of goiter, pancreatic diabetes, and several neurological diseases in humans and animals. However, the exact mechanism involved in induction of these diseases are not fully elucidated. It is believed that these effects are consequence of the toxic action of cyanide and/or its main product of transformation, thiocyanate. Thus, the objective of the present study was to determinate the effects of long term exposure to potassium cyanide (KCN) in swines, during perinatal period. Initially, it was realized a toxicokinetic study in female swines, in three different states, using thiocyanate as biomaker. Twenty two swines were randomly allocated in four groups: 6 with 60 days of age; 5 with 95 days of age, 6 with 80 days of gestation, and 6 with 21 days of lactation. All the animals received orally a single dose of 3.0 mg/kg/body weight of KCN. Thiocyanate concentrations in blood were measured within 24 h. The time of peak concentration (Tmax) and constant of elimination (Kel) was higher in lactation sows (15h; 0.045, respectively); on the other hand the higher concentrations of thiocyanate (Cmax) as well as area under the curve (AUC) were observed in pregnant sows (161.8; 158.834.34). The elimination half-life (t1/2β) and volume of distribution (Vd area) was higher in female swines with 95 days of age (41.57 h ; 1.23 L/kg), however the clearance value (Cl) was the smallest (0.017 L/kg/h). In the second step it was utilized 24 pregnancies sows, randomly allocated in four equal groups: 1 control and 3 experimental. The experimental groups was treated with 1.0, 2.0 and 3.0 mg/kg/ KCN added in commercial ration, twice a day, since 3rd week of pregnancy until the last day of gestation. The control group received only commercial ration. All fetuses were evaluated by ultra-sonographic in the 21, 35, 45, 55 e 65 days of gestation (GD). All the sows was weigthy weekly and blood colleted for biochemical evaluation. In the 110 GD, one animal per group was euthanized and fragments from some tissues were collected for histopathological study. Yet, the levels of thiocynate were evaluation in the amniotic fluid. The other sows that following gestation was collected colostrum for thiocynate evaluation levels. Histopathology revealed degenerative vacuolar alterations in the liver, pancreas, thyroid and kidney cells, and in the neurons of the central nervous system in the animals that received the KCN. In the lungs was observed widening of the epithelium alveolar. In the third step the development of the piglets was evaluate, the same biochemical parameters observed in mothers were done, with exception T3 and T4, until 45 postnatal days as well as weight and body weight gains for 120 days; in this day carcasses weights and bacon thickness were evaluated. From the biochemical parameters in relation in the piglets, it was verified that the thiocynade levels were significantly increased in several experimental groups; otherwise, too feel alterations were observed in the enzymes and other substances analyzed. The histopathological study revealed the same alterations of thyroid and lungs of the sows. In conclusion, the results of the present study support the hypothesis that the metabolism of cyanide is extremely variable, considering the age and the physiological state of female swine´s. Furthermore this study suggest that pregnancies sows are most sensible to the toxic effect, of the long-term exposition the low doses of cyanide; still, this work showed that exposition leaded the maternal and development toxicity of de pliglets.

ASSUNTO(S)

toxicocinética cyanide toxicokinetcs swine intoxication developmental toxicology toxicologia do desenvolvimento intoxicação suínos

ACESSO AO ARTIGO

Documentos Relacionados