Distribution, excretion and metabolism of lead in guinea pigs

ABSTRACT

In vivo experiments were undertaken to study the distribution as well as the toxic effects of lead on male guinea pigs, Cavia porcellia. The administration of 664 mg Pb+2/kg [which represents the 96 hours LD50, orally induced the bioaccumulation of this heavy metal in various tissues in the following order kidney >liver >bone >blood >brain. Lead administration induced its excretion by both the urinary and fecal routes. A decrease in the blood iron concentration and increases in copper, zinc and calcium levels in the blood were noticed after lead intoxication. Lead induced malformations in the RBCs and a decrease in their number. It also caused decreases in the hemoglobin content and hematocrit value. On the other hand, neither the mean corpuscular volume [MCV] nor the mean corpuscular hemoglobin concentration [MCHC] were changed. Increases in the activities of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase and amylase, were indicated in the plasma as a result of lead toxicity. However, acetyl cholinesterase activity decreased. Total bilirubin, glucose level, total lipids, total cholesterol, urea, uric acid and creatinine in the plasma were increased. While liver glycogen was decreased. On the other hand, total phospholipid and triglyceride concentrations in the plasma were not changed. These results were discussed in detail