engleski

The effect of ascorbic acid supplementation on succimer treatment during ongoing lead exposure in suckling rats

Beneficial effects of ascorbic acid supplementation on lead toxicokinetics and chelating therapy effectiveness have been repeatedly observed in experimental studies on lead-exposed adult rats. There is no available data, however, on the effects of ascorbic acid supplementation, alone or in combination with a chelator, on lead toxicokinetics in suckling mammals. In this investigation we evaluated the effect of ascorbic acid supplementation, alone or combined with succimer (meso-dimercaptosuccinic acid), on lead retention in suckling rats concomitantly exposed to lead. Suckling Wistar rats were administered orally L-ascorbic acid (25 or 650 mg/kg b. wt. a day) and/or succimer (91 mg/kg b. wt. a day) during eight-day oral exposure to lead (as acetate, 2 mg lead/kg b. wt. a day). On experiment day nine, pups were killed and lead concentrations in the liver, kidneys, brain and skeleton were analyzed by atomic absorption spectrometry. Ascorbic acid supplementation did not reduce tissue lead retention. On the contrary, in supplemented rats lead concentration increased in the kidneys and bone by 70% and 24%, respectively. As expected, succimer efficiently decreased lead in all analyzed tissues (by 32% to 83%). Supplementation with higher dose of ascorbic acid substantially decreased succimer efficacy, and lower dose did not affect succimer chelation properties. To conclude, ascorbic acid supplementation in suckling rats concomitantly exposed to lead has no beneficial effect on lead retention and, when administered at a high dose, it even reduces efficacy of succimer treatment. The findings suggest that special concern is necessary when ascorbic acid supplementation is considered in lead-exposed sucklings, especially during concurrent succimer chelation therapy.

ascorbic acid; succimer; lead; suckling rats

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