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A murine whole organ metanephric culture system was designed to study the developmental aspects of mammalian nephrogenesis. Metanephros and ureteric bud were removed from CFI albino mouse embryos at 13.5 +/- 0.4 days gestation, and grown in Dulbecco's modified Eagle's Minimal Essential Medium supplemented with 20 per cent donor bovine serum at 37C in a mixed air--5 per cent CO2 environment. Under the experimental conditions employed, the metanephric explants showed organotypic tubular and glomerular epithelial development. A well-developed proximal tubule with microvilli, and characteristic intracellular organelles and intercellular junctions developed by 72 hours of culture. By 120 hours of culture, unique devascularized glomeruli consisting of parietal and visceral epithelial layers formed. The glomerular visceral epithelial cells formed foot processes and slit pore diaphragms, and produced islands of basement membrane. No endothelial or mesangial elements were present at any stage in organ culture development, indicating that advanced nephrogenesis can occur following initial epithelial-mesenchymal induction despite the absence of vascularization. The whole organ culture model system isolates renal structural development from the influences of perfusion and urine formation. The system thus affords the opportunity to study normal, as well as abnormal mammalian renal development under highly controlled experimental conditions.

Adrenocortical carcinoma tissue removed from a mildly hirsute 16-year-old girl was cultured in order to assess steroidogenesis and responsiveness of the cells to adrenocorticotropic hormone (ACTH), human chorionic gonadotropin (HCG), and insulin. The cells in culture produced large amounts of androstenedione and testosterone; however, production of cortisol, which was initially high, decreased with time. No aldosterone, estrone, or estradiol was produced in vitro. Both monolayer cells maintained for 6 weeks and organ culture explants maintained for over 3 days responded to ACTH (10(-7) M) with increased production of androgens (testosterone, androstenedione, dehydroepiandrosterone) but decreased production of cortisol as measured by radioimmunoassay of steroids in the culture media. Concomitant with decreased cortisol production was the enhanced formation of 11-deoxycortisol in cells exposed to ACTH, suggesting impaired 11 beta-hydroxylation. Tissue exposed to HCG (10(-7) M) in organ culture showed an increase in androgen production over control levels, but no significant effect of HCG on glucocorticoid production was found. Tumor cells differed in their androgen response to ACTH and HCG, with enhanced adrenal androgens in the presence of ACTH and more gonadal-type androgens after exposure to HCG. Insulin exposure had no effect on production of either androgen or glucocorticoid by tumor tissue in organ culture. Thus, this adrenocortical carcinoma showed marked androgen production in culture which was enhanced in different ways by ACTH and HCG. 11 beta-Hydroxylation was impaired with time in culture. No specific effect of insulin on steroidogenesis was noted.

The rate of adrenal protein degradation appears to be slower in rats to which ACTH (adrenocorticotrophin) has been chronically administered. As measured by the exponential decay of radioactively labelled adrenal protein in vivo, the mean half-lives of total protein and of mitochondrial, microsomal and 18000g-supernatant protein were significantly longer in ACTH-treated animals. Experiments in which either [(3)H]leucine or NaH(14)CO(3) was used to label proteins showed that of the fractions studied, the effect on mitochondrial protein degradation was most pronounced. The half-lives of the same subcellular fractions in rat liver were not affected by ACTH. The possibility that the results might have been caused by changes in radioisotope reutilization and pool size is discussed.

Normal adrenal and adrenal tumor cells from a female infant with a virilizing adrenal tumor were grown in tissue culture as monolayers for a period of 7 weeks. Half of the cultures were exposed to ACTH (0.1 U/ml). The cells grew well and continued to produce steroid hormones over the entire period in culture. Production of steroid hormones was measured by RIA of individual steroids in the culture medium. Unstimulated normal and tumor cells produced equivalent amounts of cortisol, 11 beta, 18, 21-trihydroxy-4-pregnene-3,20-dione, and 18,21-dihydroxy-4-pregnene-3,20-dione, but tumor cells produced lesser amounts of dehydroepiandrosterone (DHA), androstenedione, testosterone, and progesterone. Normal cells exposed to ACTH showed an increase in all steroids measured, whereas ACTH-exposed tumor cells showed an increase principally in DHA consistent with a deficiency in 3 beta-hydroxysteroid dehydrogenase activity. Circulating levels of DHA, androstenedione, and testosterone were elevated in the patient before removal of the adrenal tumor. The production of androgens by tumor cells in vitro resembled the pattern of circulating steroids in vivo. These studies demonstrate that tissue culture of human adrenal cells provides a means both to determine their biochemical characteristics and to investigate their responses to exogenous hormones.

Ribonucleic acid extracted from either adrenal or testis altered the enzyme activity of adrenals and ovaries maintained in organ culture. The pattern of steroid hormone synthesis of the cultured endocrine tissue reflected the origin of the RNA.

The pattern of steroid synthesis in human fetal testes and adrenals was altered by prior exposure, in organ culture of the explants, of one gland to the ribonucleic acid extracted from the other gland. The new pattern reflected the origin of the RNA.