title: DDT increases hepatic testosterone metabolism in rats.
abstract: DDT and its metabolites are considered as endocrine disruptors able to promote hormone-dependent pathologies. We studied the effects of technical-grade DDT on hepatic testosterone metabolism and testosterone hydroxylase activity ratios in the rat. Male and female Wistar rats were treated by gavage with a single dose of technical-grade DDT (0, 0.1, 1, 10, and 100 mg/kg body weight) and killed 24 h later. Hepatic microsomes were incubated with [4-14C]-testosterone and the metabolites were separated by thin-layer chromatography and quantified by radio scanning. DDT increased testosterone biotransformation and modified the profile of metabolites produced in a sex-dependent manner. Males treated with a representative dose (10 mg/kg) produced relatively less androstenedione (AD), 2alpha-hydroxytestosterone (OHT), and 16alpha-OHT but higher 6beta-OHT whereas treated females produced less 7alpha-OHT and AD but higher 6beta-OHT and 6alpha-OHT than their respective controls. In both sexes DDT decreased the relative proportion of AD and increased that of 6beta-OHT suggesting that the androgen-saving pathway was affected. The testosterone 6alpha-/15alpha-OHT ratio, a proposed indicator of demasculinization, was increased in treated males. This effect was in agreement with the demasculinizing ability proposed for DDT. The effects on 6alpha-/16alpha-OHT and 6-dehydrotestosterone/16alpha-OHT ratios followed a similar tendency, with the ratio 6alpha-/16alpha-OHT being the most sensitive marker. Interestingly, these ratios were reduced in treated females suggesting that technical-grade DDT shifted testosterone hydroxylations toward a more masculine pattern. Thus, technical-grade DDT altered the hepatic sexual dimorphism in testosterone metabolism and decreased the metabolic differences between male and female rats.
authors.affiliation: Sección de Toxicología, Cinvestav-IPN, PO Box 14-740, Mexico DF, Mexico.
authors.forename: Adolfo
authors.initials: A
authors.lastname: Sierra-Santoyo
authors.forename: Manuel
authors.initials: M
authors.lastname: Hernández
authors.forename: Arnulfo
authors.initials: A
authors.lastname: Albores
authors.forename: Mariano E
authors.initials: ME
authors.lastname: Cebrián
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001711:Biotransformation; D003634:DDT / Q000633:toxicity*; D005260:Female; D006900:Hydroxylation; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics; D013739:Testosterone / Q000378:metabolism* / Q000493:pharmacokinetics
chemical_list: D013739:Testosterone; D003634:DDT