Abstract

Lead is a well know neurotoxic metal whose exposure has been associated with hyperglycemia and insulin resistance. Sucrose is a worldwide consumed foodstuff and experimental data have indicated that its intake can disrupt glucose metabolism in different animal models. The aim of this study was to investigate whether the simultaneous exposure to these agents could enhance the incidence of orofacial dyskinesia (OD) as well as alter behavioral and hematological parameters in aging rats. The experiments were conducted in female Wistar rats, which received lead acetate (Pb²⁺ 100 or 400 ppm) in drink water, 20% of sucrose or sucrose plus lead (100 or 400 ppm) for 12 months. The incidence of OD increased significantly as a function of age. The ingestion of lead and/or sucrose per se was not associated with an increase in OD occurrence. However, Pb²⁺ (400 ppm) when associated with sucrose decreased OD incidence. The locomotor activity of animals decreased in function of age, but was not changed by sucrose plus Pb²⁺ consumption. In addition to body weight gain, sucrose intake lowered the hematocrit and increased the blood levels of insulin and glucose of animals. Most of these effects were not induced and/or exarcebated by Pb²⁺. Our findings confirm that the aging culminates with OD onset and that the chronic consumption of Pb²⁺ or sucrose did not cause further increase in this condition. It is possible that some adaptative mechanism(s) have been developed to block the neurotoxicity of Pb²⁺ and/or sucrose after long-term exposure as verified in locomotor activity and OD. Interesting, here we described for the first time that prolonged ingestion of sucrose causes anemia in aging rats.

Keywords: Lead acetate; Sucrose; Orofacial dyskinesia; Anemia