You are here:
MATURATIONAL CHANGES IN DERMAL ABSORPTION OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) IN FISCHER 344 RATS
Citation:
Anderson, Y., J. Jackson, AND L. Birnbaum. MATURATIONAL CHANGES IN DERMAL ABSORPTION OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) IN FISCHER 344 RATS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-93/331 (NTIS PB93229490), 1993.
Description:
An earlier study indicated that dermal absorption of a 40 nmol dose of TCDD decreased with aging in rats, suggesting that the potential for systemic exposure following dermal contact would be decreased in older age groups. his study examined maturational changes in potential for systemic exposure to TCDD following dermal application of a low dose (200 pmol) in male Fischer 344 rats. bsorption, tissue distribution and elimination of TCDD, measured as TCD9-derived radioactivity, were examined 72 hrs after dermal application of 200 pmol H-TCDD in 60 ul acetone over 1.8 cm2 of the interscapular region of 3, 5, 8, 10, and 36 wk old rats. he application site was covered with a perforated metal cap; animals were held in individual metabolism cages. ermal absorption was greatest in 3 wk old rats(-129 pmol), decreasing to approximately 80 pmol in 5, 8, and 0 wk old rats and to 45 pmol in 36 wk old rats. n each age group, 70 to 80% of the radioactivity remaining at the application site 72 hrs after dosing could be removed with acetone swabs. hanges in distribution of absorbed TCDD-derived radioactivity to tissue depots, liver, fat, skin and muscle, reflected changes in body mass of these organs. ass of these depots was determined by whole body dissection. dipose tissue mass (Y) increased linearly with body weight (X), Y = 0.03X + 2.1 (r2 = 0.95). bsorbed TCDD-derived radioactivity was-incompletely eliminated. esults indicate that TCDD is absorbed to a greater degree through skin of very young animals and that a significant decrease in potential for systemic exposure may occur during maturation and during aging.