Irreversible Androgenic Programming at Birth of Microsomal and Soluble Rat Liver Enzymes Active on 4-Androstene-3,17-dione and 5α-Androstane-3α,17β-diol

摘要: Abstract The metabolism of 5α-[4-14C]androstane-3α, 17β-diol was studied in the microsomal fraction and 4-[4-14C]androstene-3,17-dione 105,000 x g supernatant fractions liver homogenates from male female rats sham-operated or castrated at birth age 7, 14, 30, 43 days. neonatally were treated with a single dose 1.45 µmoles testosterone propionate vehicle only. One group 0.145 µmole propionate. It found that hepatic steroid metabolizing enzyme activities irreversibly affected ("imprinted" "programmed") by testicular androgens could be classified into three categories according to their sensitivity toward "positive imprinting" (irreversible induction) "negative suppression). category enzymes (represented 5α-reductase active on 4-androstene-3,17-dione) imprinted relatively small (0.145 µmole) imprinting process complete 7 days age. A second 2α-hydroxylase 5α-androstane-3α,17β-diol, 3β-hydroxysteroid reductase 5α-androstane-3,17-dione, 17α-hydroxysteroid 5β-reductase needed high (1.45 µmoles) imprinted; almost third 16α-hydroxylase 4-androstene-3,17-dione 7α-hydroxylase 5α-androstane-3α,17β-diol) encompassed not completely age; these cases until 14 30 after birth. preputial glands shown contain regulated quite different way corresponding enzymes. activity gland 5α-reductase, when related wet tissue weight, suppressed following postpubertal testectomy, whereas stimulated similar treatment. ratio 3β- 3α-hydroxylated 5α-reduced metabolites incubations significantly sex castration, same measured much higher than determined both positive neonatal reversible androgenic stimulation reductase.