Adrenal cells bioassay

ACTH has been measured by bioassay, receptor assay, or immunoassay. Most bioassays are based on the effects of ACTH on adrenocortical cells (e.g, the stimulation of steroidogenesis or depletion of ascorbic acid). Responses are usually observed in the adrenal glands of hypophysec-tomized animals in situ or in isolated adrenal cells in vivo. In genera these bio assays are expensive and difficult to perform and are Hmited to research laboratories. Receptor assays use solubilized binding proteins obtained from normal or neoplastic adrenocortical ceUs. Only biologically active ACTH is measured, and a 10-pg/mL detection limit has been reported in unextracted plasma. These assays have limited application in the clinical laboratory partly because of the complexity and lability of receptor preparations. 

Cells have been isolated from many organs, including the pituitary, adrenal and thyroid glands, the testes and the corpus luteum. They have been used, without being maintained in vitro, for assaying the relevant hormones. Possibly the most used of such bioassays are those for LH and the structurally similar human chorionic gonadotrophin. The isolated cell bioassay of LH is used here as an example. This is an unusual isolated cell bioassay because it does assay the plasma directly in most other assays the isolated cells have become modified so that plasma is cytotoxic to them. 

Other Systemic Effects. Endocrine lesions related to 1,2-dibromoethane exposure were reported in the NCI (1978) gavage bioassay. These consisted of adrenal cortical cell degeneration in a small number of exposed male and female Osborne-Mendel rats. The possibility exists that this adrenal change represents a secondary (stress-related) effect rather than a primary effect of 1,2-dibromoethane exposure. 

Littlefield B A, Gurpide E, Markiewicz L, et al. (1990). A simple and sensitive microtiter plate estrogen bioassay based on stimulation of alkaline phosphatase in Ishikawa cells Estrogenic action of adrenal steroids. Endocrinol. 127 2757-2762. 

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