Sa. Saghir et al., Short-term distribution, metabolism, and excretion of 2,2 ',5-tri-, 2,2 ',4,4 '-tetra-, and 3,3 ',4,4 '-tetrachlorobiphenyls in prepubertal rats, ARCH ENV C, 36(2), 1999, pp. 213-220
Citations number
33
Categorie Soggetti
Environment/Ecology,"Pharmacology & Toxicology
Journal title
ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
The excretion and tissue retention of three C-14-labeled lower chlorinated
biphenyls were examined in prepubertal male and female Sprague-Dawley rats
following IV administration. Urine and feces were collected individually at
different time intervals up to 72 h for pharmacokinetic analyses. After 72
h, different organs were removed and extracted in acetone: hexane (1:1, v/
v) to determine radioactivity. Within the first 10 h after dosing, 2,2',5-t
richlorobiphenyl (PCB 18) was rapidly excreted in urine (8-18% of the admin
istered dose), whereas only 0.6-0.8% of 2,2',4,4'-tetrachlorobiphenyl (PCB
47) and 0.3-0.8% 3,3',4,4'-tetrachlorobiphenyl (PCB 77) were found in urine
during this time period. The half-life of elimination was shortest for PCB
18 (37.5 to 49.2 h). The half-lives for PCB 47 and PCB 77 were 351 to 672
h and 152 to 186 h, respectively. The cumulative total excretion (urinary fecal) of PCB 18 within 72 h was 51-62%, of PCB 77 was 22-25%, and of PCB
47 was 7-10%. No parent PCBs were detected in urine. PCB 47 accumulated pre
ferentially in adipose tissues (subcutaneous fat > mesenteric fat); relativ
ely high levels of PCB 47 were also found in adrenals, ovaries, lungs, live
r, and skin. The highest concentration of PCB 77 was found in serum, follow
ed by adipose tissues. Very low concentrations of PCB 18 were found in most
tissues; the highest being found in serum, followed by ovaries and adrenal
glands. This study suggests that prepubertal rats retain higher short-term
serum levels and have lower excretion rates than adult rats.