Steroid Hormones and the Kidney

Steroid hormones appear to act generally by binding to a high-affinity, low-capacity, steroid-specific receptor protein in the cytoplasm of target cells. Translocation of the steroid-receptor complex to the nucleus induces the transcription of RNA, which results in the synthesis of proteins respon­ sible for the physiological actions. In the kidney, receptors have been found for corticosteroids, estradiol, testosterone, and 1,25-dihydroxy-vitamin D3. The most thoroughly studied of the hormones acting on the kidney are corticosteroids, especially aldosterone. We emphasize issues that are un­ resolved or need critical evaluation; we concentrate on corticosteroids. We discuss three areas of current interest: (a) steroid receptors; (b) the role of RNA, protein, and lipid synthesis; and (c) physiological effects.