Developmental correlation of higher levels of estrogen binding by macromolecules in rat liver supernatant and of increases in plasma renin substrate levels after estrogen administration

The adult female liver supernatant contains a high affinity estrogen specific binding protein. The liver of the prepubescent female rat has less estrogen specific binding macromolecules than the adult. This difference in quantity is maintained when binding activities are partially purified by precipitation with ammonium sulfate at 30% saturation. After administration in vivo of ethinyl estradiol, plasma renin substrate (PRS) levels increase 167 per cent above control in the adult female rat. The corresponding increase is only 15 per cent in the prepubescent rat. In contrast, renin substrate levels are markedly increased in both the prepubescent and adult by administration of the glucocorticoid, dexamethasone. The substantial increase in the amount of estrogen binding and PRS responsiveness to estrogen administration with sexual maturation suggests that the estrogen binding protein may be an estrogen receptor involved in modulating synthesis of at least one plasma protein.