4 research outputs found
Effect of zinc supplementation on the distribution of lead in tissues of rats intoxicated by lead compounds
The permissible threshold level of lead in blood (Pb-B) is currently established at 5 mg dL-1,
but evidence suggests that it is impossible to determine the safety threshold for lead (Pb) and
any exposure, especially in children, must be considered as potentially harmful. Methods used to
reduce the concentration of Pb in blood (e.g. EDTA, penicillamine) are not always effective and
are associated with serious side effects. One of the proposed dietary supplements in the case of
exposure to Pb and low blood Pb concentrations is zinc (Zn), but the published literature on its
effectiveness is limited. Therefore, the aim of this study was to clarify whether Zn supplementation
may help reduce the concentration of Pb in the blood and tissues of rats, at the Pb-B level
previously recognized as safe. Tests were performed on 6-8 week old male Wistar rats. Rats were
divided into control and experimental groups: Group C – rats receiving drinking water ad libitum
for 4 weeks; Group Pb – rats receiving Pb acetate 0.1% (PbAc) in drinking water ad libitum for 4
weeks; Group Zn – rats receiving ZnCO3 300 mg kg-1 diet for 4 weeks; Group Pb+Zn – rats receiving
PbAc in drinking water ad libitum plus 300 mg ZnCO3 kg-1 diet for 4 weeks. The applied dose
of 300 mg of ZnCO3 kg-1 diet results in a high but non-toxic Zn level. The concentrations of Pb
and Zn in blood, plasma, liver and bone were determined by emission spectrometry in inductively
coupled argon plasma (ICP OES). Incidental exposure of adult rats to Pb at doses resulting in the
level of Pb in blood below the previously recognized as safe one caused: (i) increased Pb concentration
in the bones and plasma and its reduction in the whole blood and liver (ii) simultaneous
supplementation of rats exposed to Pb with a high but non-toxic dose of zinc did not result in the
reduction of the Pb concentration in the blood and tissues of rats, nor did it induce any changes in the distribution of Pb in the examined tissues (iii) supplementation of diets with a high but
non-toxic dose of Zn is not an effective method of reducing the concentration of Pb in blood at
Pb-B previously recognized as safe. However, the therapy consisting of zinc supplementation to
support the action of chelators could be crucial for the elimination of Pb from the body
Effect of zinc supplementation on the distribution of lead in tissues of rats intoxicated by lead compounds
The permissible threshold level of lead in blood (Pb-B) is currently established at 5 mg dL-1,
but evidence suggests that it is impossible to determine the safety threshold for lead (Pb) and
any exposure, especially in children, must be considered as potentially harmful. Methods used to
reduce the concentration of Pb in blood (e.g. EDTA, penicillamine) are not always effective and
are associated with serious side effects. One of the proposed dietary supplements in the case of
exposure to Pb and low blood Pb concentrations is zinc (Zn), but the published literature on its
effectiveness is limited. Therefore, the aim of this study was to clarify whether Zn supplementation
may help reduce the concentration of Pb in the blood and tissues of rats, at the Pb-B level
previously recognized as safe. Tests were performed on 6-8 week old male Wistar rats. Rats were
divided into control and experimental groups: Group C – rats receiving drinking water ad libitum
for 4 weeks; Group Pb – rats receiving Pb acetate 0.1% (PbAc) in drinking water ad libitum for 4
weeks; Group Zn – rats receiving ZnCO3 300 mg kg-1 diet for 4 weeks; Group Pb+Zn – rats receiving
PbAc in drinking water ad libitum plus 300 mg ZnCO3 kg-1 diet for 4 weeks. The applied dose
of 300 mg of ZnCO3 kg-1 diet results in a high but non-toxic Zn level. The concentrations of Pb
and Zn in blood, plasma, liver and bone were determined by emission spectrometry in inductively
coupled argon plasma (ICP OES). Incidental exposure of adult rats to Pb at doses resulting in the
level of Pb in blood below the previously recognized as safe one caused: (i) increased Pb concentration
in the bones and plasma and its reduction in the whole blood and liver (ii) simultaneous
supplementation of rats exposed to Pb with a high but non-toxic dose of zinc did not result in the
reduction of the Pb concentration in the blood and tissues of rats, nor did it induce any changes in the distribution of Pb in the examined tissues (iii) supplementation of diets with a high but
non-toxic dose of Zn is not an effective method of reducing the concentration of Pb in blood at
Pb-B previously recognized as safe. However, the therapy consisting of zinc supplementation to
support the action of chelators could be crucial for the elimination of Pb from the body