Influence of neonatal androgenization on the expression of alpha 2u-globulin in rat liver and submaxillary gland.

We studied the influence of neonatal androgenization on the serum level of alpha 2u-globulin, the level of the corresponding mRNA in liver and submaxillary gland and the concentration of an androgen and oestrogen binding protein in liver cytosol. Male rats gonadectomized on day 15 (after the neonatal surge of androgen secretion) were used as neonatally androgenized animals, their female littermates gonadectomized at the same age served as controls. Using a sensitive radioimmunoassay it could be demonstrated that only very low levels of alpha 2u-globulin are present in adult female control animals. Neonatal androgenization increases these levels some 14-fold. Stimulation with testosterone or dexamethasone results in a relative increase in the serum levels in animals of both sexes. After 11 days of treatment with testosterone propionate or dexamethasone, however, the final alpha 2u-globulin levels are respectively 1.8 times and 8 times higher in neonatally androgenized rats as compared to their female littermates. The concentration of the androgen and oestrogen binding protein in rat liver cytosol displays parallel sex differences in unstimulated animals and parallel changes after treatment with androgens and glucocorticoids. Measurements of alpha 2u-globulin mRNA by dot blot hybridization and by translation in reticulocyte lysate show a good correlation between the serum levels of alpha 2u-globulin and the corresponding mRNA in the liver. The abundance of alpha 2u-globulin mRNA in submaxillary gland is not influenced by neonatal androgens or hormone treatment during adulthood. These data suggest that neonatal androgenization directly or indirectly influences the availability for transcription and/or the transcription rate of alpha 2u-globulin genes in the liver.