US EPA

2175707 

Journal Article 

Abstract 

Distribution and kinetics of 2,4,5,2,'5'-pentachlorobiphenyl (PCB) in male rat 

Matthews, HB; Bend, , JR; Anderson, MW 

1974 

1 

Toxicology and Applied Pharmacology
ISSN: 0041-008X
EISSN: 1096-0333 

29 

1 

88 

English 

WOS:A1974T653800039 

has other version or edition 2175713 The distribution and excretion of 3,5,3',5'-tetrachlorobiphenyl in male rat
is part of a larger document 3378179 Abstracts of papers for the Thirteenth Annual Meeting of the Society of Toxicology, Washington, D.C. March 10–14, 1974

The distribution of [14C]PCB in male rats was studied at times from 5 min to 7 days after iv doses of 0.06, 0.6 and 6.0 mg/kg. The PCB was rapidly cleared from blood with liver and lean tissues being major depots at early times (<1 hr). At 5 min post dose, hepatic uptake accounted for up to 35% of the total administered radioactivity. The compound is metabolized in the liver and excreted into the bile. At all times, only parent PCB was found in blood tissues. There was a biphasic decay with time for both blood and liver concentrations of PCB. Ratios of liver-to-blood concentrations of PCB decreased from 10 at early times to a steady-state value of 3 at 12 hr. Lean tissue-to-blood concentration ratios remained near unity during the study period; however, due to its mass, lean tissue served as a major storage site for PCB at early times. Fat-to-blood ratios rose steadily over the 7-day period and fat became the major depot at later times. Fat levels of PCB were as high as 46% of the total dose and were still 19% at 7 days. After 8 hr, about 80% of unexcreted PCB was in the fat. There was no evidence for saturation of storage or excretion sites as up to a 100-fold increase in dose had little effect on relative distribution of PCB. Pre-treatment of rats with an inducer (phenobarbital) or an inhibitor (SKF-525A) of hepatic microsomal enzymes had marked effects on the distribution pattern of PCB in all tissues 24 hr after dosing, particularly, in the fat. The results indicate that liver and lean tissue are the major sites of PCB clearance from blood at early times after dosing and storage in fat is the major determinant of PCB persistence in the body. 

Thirteenth Annual Meeting of the Society of Toxicology 

Washington, D.C. 

March 10–14, 1974