In vivo and in vitro dermal absorption of benzo[a]pyrene in rat, guinea pig, human and tissue-cultured skin.
Cross-species in vitro dermal absorption tests were conducted with 14C-labelled benzo[a]pyrene dissolved in acetone and applied to dermatomed skin (0.5 mm thickness) at comparable dose rates (8-13 micrograms/cm2). Skin absorption was determined using the Bronaugh in vitro flow-through procedure. The percentage (%) dermal absorption included the % 14C-activity detected persisting in the skin added to that detected in the receiver solution. Listed in decreasing order, total % in vitro dermal absorption obtained by 48 h postexposure was: 95 +/- 9.6% (rat), 51 +/- 3.0% (hairless guinea pig), 43 +/- 8.7% (human; 50-year-old), 34 +/- 12.4% (Testskin) and 23 +/- 5.3% (human; 32-year-old). Comparative in vivo studies demonstrated urinary recovery of 8 +/- 1.8% and 25 +/- 5.0% for rats (dose rate: 6 micrograms/cm2) and hairless guinea pigs (dose rate: 9 micrograms/cm2), respectively. Total faecal recovery was 61 +/- 6.0% and 43 +/- 6.1% for rats and guinea pigs, respectively. Necropsies conducted at 14 days postexposure demonstrated total 14C-activity tissue recoveries of 0.5 +/- 0.13% and 0.6 +/- 0.17% in rats and guinea pigs, respectively. Including the 14C-activity extracted from the skin removed from the dose site at 14 days postexposure, the total % in vivo dermal absorbtion was 70 +/- 7.6% and 68 +/- 9.3% for rats and guinea pigs, respectively. In summary, the in vitro data was consistent with the in vivo data in demonstrating that 14C-benzo[a]pyrene was well absorbed through skin.
Moody
R P
RP
Health Canada, Environmental Health Centre, Ottawa, Ontario.
Nadeau
B
B
Chu
I
I
D000042:Absorption; D000287:Administration, Topical; D000328:Adult; D000818:Animals; D001564:Benzo(a)pyrene / Q000008:administration & dosage / Q000493:pharmacokinetics*; D046508:Culture Techniques; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D008297:Male; D008875:Middle Aged; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000378:metabolism*; D013045:Species Specificity; D013550:Swimming; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics
D014874:Water Pollutants, Chemical; D001564:Benzo(a)pyrene