Factors affecting the absorption and excretion of lead in the rat

Journal Article · Sat Apr 01 04:00:00 EST 1978 · Gastroenterology; (United States)

OSTI ID:5246356

Conrad, M E; Barton, J C

A reliable method for studying lead absorption and excretion in rats is described. Lead absorption occurs primarily in the duodenum where lead enters the epithelial mucosal cells. There is a relative mucosal block for lead with increasing intraluminal doses. Certain substances which bind lead and increase its solubility enhance its absorption. Iron, zinc, and calcium decrease the absorption of lead without affecting its solubility, probably by competing for shared absorptive receptors in the intestinal mucosa. The total body burden of lead does not affect lead absorption. Thus, lead does not have a feedback mechanism which limits absorption. Lead absorption is increased during rapid periods of growth and in iron-deficient animals. It is diminished with starvation and in iron-overloaded animals. The excretion and kinetics of tracer doses of radiolead were quantified. Erythrocytes seem to serve an important role in transport. Excretion occurs in urine and stool. Bile is an important route of excretion in the gut. Although most of a tracer dose is rapidly excreted, the excretory process is limited permitting lead accumulation primarily in bone.

• Research Organization: Univ. of Alabama, Birmingham
• OSTI ID: 5246356
• Journal Information: Gastroenterology; (United States), Journal Name: Gastroenterology; (United States) Vol. 74:4; ISSN GASTA
• Country of Publication: United States
• Language: English

Related Subjects

550501 -- Metabolism-- Tracer Techniques
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL LOCALIZATION
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY BURDEN
BODY FLUIDS
CLEARANCE
DIGESTIVE SYSTEM
ELEMENTS
ERYTHROCYTES
EXCRETION
GASTROINTESTINAL TRACT
INTESTINAL ABSORPTION
ISOTOPE APPLICATIONS
LEAD
LEAD ISOTOPES
MAMMALS
MATERIALS
METABOLISM
METALS
RADIONUCLIDE KINETICS
RATS
RESPONSE MODIFYING FACTORS
RODENTS
TOLERANCE
TOXICITY
TRACER TECHNIQUES
UPTAKE
VERTEBRATES