Calcium Supplementation Efficiently Reduces Lead Absorption in Suckling Rats*

Abstract

The effect of calcium supplementation on tissue lead was evaluated in suckling Wistar rats. Such data are not yet available in the literature. The following artificial feeding regimen was used for calcium supplementation: cow's milk by addition of 1%, 3% or 6% Ca as CaHPO 4 ¿2H 2 O suspension to increase the daily calcium intake about 1.4, 2 or 3 times above control values. Artificial feeding was applied during 7 hr each day for nine consecutive days (from day 6 through 15 after birth). The effect of such treatment on lead absorption and elimination was evaluated in two separate experiments: calcium supplementation during oral lead exposure (as acetate; daily dose 2 mg Pb/kg body wt.; total Pb dose 18 mg/kg body wt.) or after a single intraperitoneal lead administration (5 mg/kg body wt.). At the end of experiments, lead in tissues (liver, kidneys, brain and carcass), and essential elements (Ca, Fe, Zn, Cu) were analysed by atomic absorption spectrometry. Calcium supplementation caused a statistically significant decrease of lead in all tissues of sucklings orally exposed to lead. This decrease was dose-related being about 1.3, 1.5 and 2 times lower in groups supplemented with 1%, 3%, or 6% calcium compared to controls, respectively. Increased calcium intake had no effect on incorporated lead after parenteral lead exposure. Calcium supplementation increased carcass calcium and had no effect on trace elements in tissues, pups' general appearance and body weight gain. It is concluded that higher calcium intake might be a way of efficient reduction of lead absorption during the suckling period.

Succimer treatment and calcium supplementation reduce tissue lead in suckling rats

“…These results, which are in agreement with our previous experiments (Varnai et al, 2001a), confirm the findings of other authors that calcium primarily reduces lead absorption and does not significantly influence lead elimination (Barton et al, 1978;Quarterman et al, 1978). ), 72 h prior to beginning the Ca and DMSA treatments.…”

“…Calcium supplementation caused an increase in carcass calcium, as noticed earlier (Varnai et al, 2001a), but in this experiment it was not statistically significant. The decrease in copper values in DMSA-treated pups is in agreement with previous data (Tandon et al, 1983;Smith et al, 2000), because it is known that DMSA is also used as a chelating agent for enhancing copper elimination (Ding & Liang, 1991;Ren & Yang, 1997).…”

Assessment of Lead Ecotoxicity in Water using the Amphibian Larvae (Xenopus laevis) and Preliminary Study of its Immobilization in Meat and Bone Meal Combustion Residues

“…Quarterman and Morisson (1975) established that the absorption and retention of lead in rats is especially influenced by Ca and phosphate which both decrease the retention and increase the excretion of lead. Meredith et al (1977), Bogden et al (1992) and more recently Varnai et al (2001) also showed that higher Ca intake might be a way of reducing Pb absorption in rats. In the same way, Quaterman et al (1978), Spickett and Bell (1983) and more recently Cortina-Ramirez et al (2005) also showed that increased dietary phosphate limits Pb intestinal absorption in rats.…”

Effect of calcium supplementation on lead-induced genotoxicity and bioaccumulation in suckling Wistar rats

“…In addition, calcium supplementation in human infants was reported to inversely correlate with absorption and retention of lead (Ziegler et al 1978). Experimental studies on calcium supplementation in suckling rats have been conducted and significant decrease of lead in all tissues and increase in carcass calcium have been reported, but no effects on trace elements in tissues and the general appearance and the body weight gain of the sucklings were observed (Varnai et al 2001).…”