Excretion of DDT compounds in rat milk

Abstract

The concentrations of p,p′-DDT (1,1,1-trichloro-2,2-bis( p-chlorophenyl)-ethane), o,p-DDT (1,1,1-trichloro-2-( o-chlorophenyl)-2-( p-chlorophenyl)-ethane), p,p′-DDE (1,1-dichloro-2,2-bis( p-chlorophenyl)ethylene, and p,p′-TDE (DDD) (1,1-dichloro-2,2-bis( p-chlorophenyl)ethane) in milk, liver, and perirenal fat lipids of 4 female Sprague-Dawley-derived rats orally exposed to 20 or 200 ppm of technical DDT from weaning to sacrifice are presented. Milk samples were obtained from stomachs of suckling pups. One suckling was selected from each litter of 2 dams in the 20 ppm DDT diet group and 2 dams in the 200 ppm DDT diet group on days 1, 3, 6, and 10 of first lactation periods and days 1 and 10 of second lactation periods. Four milk samples collected in the same manner from the first lactation period of a control dam were also analyzed. Perirenal fat and livers were obtained from dams at weaning of second litters. With the exception of o,p-DDT, the concentrations of DDT compounds are greater in early milk than in later milk. The relative concentration of o,p-DDT in biological samples is considerably less than that in the DDT diets. Milk and perirenal fat lipids in each dam are very similar in pattern of distribution of DDT compounds. Liver lipids contain larger concentrations of p,p′-TDE and smaller concentrations of p,p′-DDT than milk or perirenal fat. The milk lipid: feed DDT ratio is considerably greater than 1 in the rat.