Retention, distribution, and excretion of lead by the rat after intravenous injection.

Abstract

The distribution and excretion of lead was studied during a period of about a week after a single intravenous injection of 203Pb as chloride accompanied by less than 1 ,tg of lead carrier. The peak concentration in venous blood was reached after about an hour when it contained 35 to 40 % of the administered activity. The subsequent decline in concentration was much more rapid than is observed in man. The main storage organs were the kidneys and bone. Initially, 20 % of the dose could be accounted for in the kidneys and the biological half-life was about 100 hours. The level in bone built up rapidly at first and then more slowly. After a week, between 25 and 30°, of the dose was present in bone.Petrol engine exhaust aerosols labelled with 203Pb have been administered to volunteers by Chamberlain et al. (1975) to study their deposition in the respiratory tract and the absorption of the associated lead. In complementary investigations, similar aerosols were administered to rats to' study, in greater detail than is possible with volunteers, the distribution of absorbed lead at various times. To provide, for comparative purposes, information on the metabolism of lead introduced directly into the blood stream rats were injected intravenously with 203Pb in the form of chloride. The results of these investigations are described in this report and an account of the absorption and metabolism of lead administered to rats in exhaust particulates will be given elsewhere.

Protection against lead contamination by strains of lactic acid bacteria from<br>fermented camel milk

“…The level in bone built up rapidly at first and then more slowly. After a week, between 25 and 30% of the dose was present in bone (Castellino and Aloj, 1964;Morgan et al, 1977).…”

An age-specific kinetic model of lead metabolism in humans.

“…Results of studies on dogs and rodents indicate that the kidneys may accumulate as much as 15-20% of intravenously injected radiolead within the first 1-2 hr, that the preponderance of the deposited activity represents filtered lead, and that a substantial portion of the early accumulation is reabsorbed or lost in urine within a few hours (118)(119)(120). In rats, the kidneys contained roughly 10% of the intravenously injected amount after 1 day but less than 2% after 9 days (82).…”

Dose Dependent Transfer of 203Lead to Milk and Tissue Uptake in Suckling Offspring Studied in Rats and Mice

“…In the present study, approximately I-2% of the amount of lead in blood was found in plasma in rats. In other studies the plasma lead concentration has been reported to be 4%) (Castellino & Aloj 1964) and 2% (Morgan et al 1977) of the concentration in whole blood in the rat. The days.…”

“…The binding of lead to erythrocytes probably also influences the excretion of lead into milk. In humans, approximately 99% of the lead in blood is associated with red blood cells (de Silva 1981; Manton & Cook 1984;Campbell et al 1984) while the corresponding figure in rats is about 96-98% (Castellino & Aloj 1964;Morgan et al 1977). Keller & Doherty (1980) suggested in mice, that approximately 99% of the blood lead is associated with red blood cells.…”