Time-dependent uptake and metallothionein-binding of gold, copper and zinc in the rat kidney.
In rats, in which the whole body burden of Au decreases rapidly, but biphasically, maximum kidney concns are not attained until 10-15 days after a single intraperitoneal dose of either Au(I) or Au(III). The concn of metallothionein-bound Au and of total kidney Cu, which also increases after the administration of the Au compounds, however, reach maxima at 5 days. Between at least 6 and 24 hr after Au treatment, the increases in the concn of Au and Cu in the metallothionein fraction are highly correlated. Measurements on the kidneys of animals at early times (15 min-6 hr) after dosing with Au(III) indicate that the Zn content of the (endogenous) metallothionein is depressed during the first hour, shows a transient increase at 2 hr and then falls to a minimum at 6 hr. Subsequent (6-24 hr) changes in metallothionein-bound Zn parallel those of metallothionein-bound Au and Cu. It seems, therefore, that Au and Cu are incorporated simultaneously into rat kidney metallothionein and this incorporation may be mediated by an initial displacement of Zn. In rats exposed to five doses of Au(III) the half-times of total and metallothionein-bound Au in the kidneys are appreciably longer than those in animals given a single dose. In both groups, the concns of Cu and Zn in the renal metallothionein do not decrease in parallel with that of Au, but change roughly in proportion to their whole kidney concns. In consequence, the metal composition of the metallothionein fraction, which remains above the endogenous concn in the normal kidney throughout an experimental period of 90-140 days, alters considerably with time.
D000818:Animals; D001667:Binding, Competitive; D003300:Copper / Q000378:metabolism*; D005260:Female; D006046:Gold / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D008667:Metalloproteins / Q000378:metabolism*; D008668:Metallothionein / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D015032:Zinc / Q000378:metabolism*
D008667:Metalloproteins; D006046:Gold; D003300:Copper; D008668:Metallothionein; D015032:Zinc