Record Display for the EPA National Library Catalog

RECORD NUMBER: 22 OF 36

OLS Field Name OLS Field Data
Main Title Mechanisms of cadmium absorption in rats /
Author Foulkes, E. C. ; Johnson, D. R. ; Sugawara, N. ; Bonewitz, R. F. ; Voner, C.
Other Authors
Author Title of a Work
Foulkes, Ernest C.,
Johnson, D. R.
Sugawara, N.
Bonewitz, R. F.
Voner, C.
Kowal, N. E.
CORP Author Cincinnati Univ., OH.;Health Effects Research Lab., Cincinnati, OH.
Publisher U.S. Environmental Protection Agency, Research and Development, Health Effects Research Laboratory,
Year Published 1981
Report Number EPA-600/1-81-063; EPA-R-805840
Stock Number PB82-108184
OCLC Number 58675188
Subjects Cadmium. ; Intestinal absorption.
Additional Subjects Cadmium ; Absorption ; Toxicology ; Metals ; Intestines ; Laboratory animals ; Toxic substances ; Heavy metals ; Bioaccumulation
Internet Access
Description Access URL
https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=600017R1.PDF
Holdings
Library Call Number Additional Info Location Last
Modified
Checkout
Status
ELBD  EPA 600-1-81-063 AWBERC Library/Cincinnati,OH 03/31/2005
NTIS  PB82-108184 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 01/01/1988
Collation vii, 50 p. : ill. ; 28 cm.
Abstract
This study was undertaken in order to help clarify the factors which determine the fractional absorption of an oral load of cadmium (Cd) from the intestine of the rat. The experiments utilized intact segments of intestine, perfused or incubated in situ with their blood supply intact. Absorption of Cd from the jejunal lumen can be ascribed to a saturable membrane system; that is, after short periods of exposure essentially all the metal removed from the lumen was recovered in mucosal tissue (Step I). The second step in Cd absorption, i.e., transfer of the metal from mucosa into blood, proceeded at only 1-2% of the rate of uptake from the lumen (Step I). No evidence was obtained for a role of metallothionein in the mucosal retention of Cd. Step I of Cd absorption was inhibited by a variety of exogenous and endogenous factors. Thus, zinc was found to depress Cd transport in an apparently competitive manner. Addition of milk to the lumen also inhibited Cd uptake, an effect entirely due to the Ca content. Bile salts act as endogenous modulators of Cd absorption; their effect may be related to micelle formation. The research also included studies of duodenal and ileal Cd transport. Ileal Cd absorption differed from that in the jejunum by a relatively much faster Step II. Unlike the low ratio of Steps II/I for the toxic metal in the jejunum, the ratio for the essential metals Cu and Zn was much higher (about 50%). Absorption of Cd by the gut in neonatal rats proceeded much faster than in adults; reasons for this difference have not yet been clarified. Another question remaining under study is the extent to which different metals such as Cd and Zn share common absorptive mechanisms.
Notes
"Project Officer, N.E. Kowal." "Grant R805840." "PB82-108184." "September 1981." "EPA-600/1-81-063."