We studied the effects of weight loss and non-weight bearing exercise (swimming) on blood and organ lead and essential metal concentrations in rats with prior lead exposure. Weanling female Sprague-Dawley rats (n = 37) received lead as the acetate for two weeks in their drinking water followed by a four-day latency period without lead exposure. Rats were then randomly assigned to one of the 6 treatment groups: weight maintenance (WM) with ad lib feeding, moderate weight loss (MWL) with 20% food restriction, and substantial weight loss (SWL) with 40% food restriction with or without swimming. Blood lead concentrations were measured weekly. The rats were euthanized after four weeks and the brain, liver, kidney, skeletal muscle, spinal column bones, and femur harvested for analysis for lead, calcium, copper, iron, magnesium and zinc using atomic absorption spectrophotometry. Rats fed restricted diets had consistently higher blood lead concentrations than their ad lib controls. Rats in the SWL group had higher organ lead concentrations than the rats in the WM group. Rats in the MWL group had intermediate values. There were no significant differences between the swimming and non-swimming groups. Weight loss also increased organ iron concentrations, but not those of the other metals studied. The results demonstrate that lead and iron stores are conserved during weight loss. It is possible that weight loss, especially if rapid, could result in lead toxicity.
|Published - Mar 20 1998
All Science Journal Classification (ASJC) codes
- Molecular Biology