Improved radioimmunoassay for 11-deoxycortisol (compound S) in plasma.
(57/79)
We describe a radioimmunoassay for 11-deoxycortisol (Compound S) that involves preliminary chromatography on Sephadex LH-20, to isolate 11-deoxycortisol from crossreacting structurally related steroids. Pools with means of 3.4, 12.9, and 69.9 micrograms/L gave intra-assay coefficients of variation of 9.7, 9.6, and 11.4%, respectively; pools with means of 4.6, 27, and 95 micrograms/L gave inter-assay CV's of 10.1, 9.7, and 6.2%, respectively. A normal range (mean +/- 2SD) of 0.5 to 12.0 micrograms/L was obtained. This procedure is useful for the specific determination of 11-deoxycortisol, commonly determined in blood as part of the metyrapone test for assessing pituitary corticotropin reserve. (+info)
Effect of glucocorticoid hormones in vitro on the structural integrity of nuclei in corticosteroid-sensitive and -resistant lines of lymphosarcoma P1798.
(58/79)
Exposure of rat thymus cells to glucocorticoids leads to a decreased ability of nuclei to survive the lysis of whole cells by hypotonic shock. In this study, a similar glucocorticoid-induced increase in "nuclear fragility" was found in both corticoid-sensitive and -resistant lines of P1798 mouse lymphosarcoma cells. In corticoid-sensitive cells a small increase in nuclear fragility is seen after a 2-hr exposure to cortisol (10(-6) M); by 3 hr it is 20 to 40% above control values. This effect appears to be a specific glucocorticoid response. Both cortisol and dexamethasone at 10(-7) M produce an effect, 10(-6) M testosterone is inactive, and cortexolone, which binds to glucocorticoid receptors, reduces the effect. Cycloheximide, at concentrations that inhibit protein synthesis, also blocks this effect. While the corticoid-resistant line also demonstrates an effect of similar magnitude, it requires a much longer exposure to the hormone (6 hr). Distinct differences in the "hardiness" of the two cell lines (nuclei of the corticoid-resistant line are less fragile) measurable in the absence of hormones appears to account for the differential susceptibility to steroids. On this basis a new theory of resistance is advanced where the emergence of resistance is related to structural differences in the cells. (+info)
Does the corticoadrenal adenoma with "pre-Cushing's syndrome" exist?
(59/79)
An adrenal tumor was discovered fortuitously in a patient with no clinical features of Cushing's syndrome. On adrenal imaging, there was good uptake in the nodule but no visualization of the contralateral adrenal. The latter was seen, however, in a second scan performed under ACTH treatment. In the hormone assessment, basal cortisol and 17-hydroxycorticoids were normal and cortisol diurnal variation was near normal, but a dexamethasone suppression test and ACTH responses to metyrapone and insulin hypoglycemia were abnormal. Eight months after excision of a spongiocytic-type adenoma, the remaining adrenal was visible on scintigram and the hormonal tests were normal. This pattern suggests that the clinical Cushing's syndrome but enough to suppress partially ACTH and, consequently, visualization of the contralateral gland. (+info)
Be13, a human T-leukemia cell line highly sensitive to dexamethasone-induced cytolysis.
(60/79)
A unique human T-leukemia cell line highly sensitive to dexamethasone-induced lysis is described. The cell line designated Be13 is killed readily within 24 hr by 10(-9) M dexamethasone. No lysis is induced by nonglucocorticoid steroids. The lysis is mediated via specific cytoplasmic receptors and is efficiently blocked by the antagonist cortexolone. The inhibiting effect of actinomycin D and cycloheximide on the lytic process suggests the involvement of gene activation and destruction of the cells by an "autolytic protein." Kinetic studies imply that the lytic process is induced during a distinct phase of the cell cycle. Dexamethasone, however, does not cause an arrest in a distinct phase of the cell cycle. The Be13 cell is a unique human cell line killed directly by glucocorticoids, and it may serve as a suitable in vitro model for studying the lytic effect of glucocorticoids on the proliferating compartment of human leukemias. (+info)
Salt loss in congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency.
(61/79)
Nine patients with 11 beta-hydroxylase deficiency had 13 episodes of gastroenteritis requiring hospital admission and fluid administration. Eight episodes were accompanied by hyponatraemia and salt loss. The salt losing patients were treated with excessive glucocorticoid and those with normal serum sodium concentrations were treated with inadequate glucocorticoid. Excessive glucocorticoid suppressed deoxycorticosteroid secretion, resulting in salt loss. (+info)
Polarization fluoroimmunoassay of 11-deoxycortisol in serum and saliva.
(62/79)
We developed polarization fluoroimmunoassays for 11-deoxycortisol in serum and saliva. To avoid interfering factors, the steroid was initially extracted from the biological fluids with dichloromethane. Assays could then be completed without any further separation procedures or need to correct for blank signals. The serum assay was suitable for following the response to the metyrapone test and results correlated acceptably with those by an established, specific, direct 125I-radioimmunoassay. The method is not sufficiently sensitive to detect 11-deoxycortisol in normal saliva, but greatly increased concentrations were found in post-metyrapone saliva and results agreed well with those by the radioimmunoassay as modified for salivary assay. Salivary 11-deoxycortisol assay would provide a convenient means of monitoring results of the metyrapone test. (+info)
Glucocorticoids stimulate adrenergic differentiation in cultures of migrating and premigratory neural crest.
(63/79)
Glucocorticoid hormones stimulate catecholamine (CA) anabolism in a variety of adrenergic derivatives of the neural crest. We describe work performed to investigate the action of these steroids on the catecholaminergic differentiation of neural crest cells themselves. Crest was taken from the trunk level of 2-day quail embryos, before migration had begun, and was cultured in vitro. Adrenergic differentiation, characterized by the ability of the cultures to synthesize and store CA, was minimal and was not improved when glucocorticoids were added to the medium. In contrast, extensive adrenergic differentiation occurred when neural crest cells, removed from the embryo 24 hr later, toward the end of their migratory phase, were cultured with the sclerotomal component of the somite (their immediate embryonic microenvironment). This process was considerably stimulated by corticosteroids; the rate of conversion of [3H]tyrosine to intracellular CA (norepinephrine, epinephrine, and dopamine) was 2 to 3 times higher in cultures exposed for 7 days to 10(-6) to 10(-7) M hydrocortisone, corticosterone, or dexamethasone, and the diameter of the dense-core vesicles seen in cell bodies and processes after permanganate fixation was strikingly increased. The effect was specific for the adrenergic phenotype in that acetylcholine synthesis by the cultures was consistently unaffected by hormone treatment. We infer that glucocorticoids do not trigger adrenergic differentiation, but that they selectively enhance catecholaminergic properties in crest cells that have already been exposed to an appropriate signal of another kind. This conclusion is strengthened by the observation that glucocorticoids stimulated the development of CA-producing cells from premigratory crest grown in the presence of somites and notochord, postulated sources of factors initiating adrenergic differentiation in the embryo. Although the intervention of glucocorticoids in vivo at very early embryonic stages remains to be established, our results indicate that neural crest derivatives would be potentially responsive to these hormones as soon as the sympathetic ganglia form. (+info)
Nuclei and DNA-binding form of the steroid receptor complex in the liver and the ventral prostate of rats.
(64/79)
Repeated treatments of the liver cytosol prelabeled with 3H-dexamethasone with DNA-cellulose followed by treatments with purified liver nuclei enabled us to assess the amount of two forms of dexamethasone-receptor complex, one binds only to nuclei and the other binds to DNA and nuclei. The comparable amount of these two forms of the receptor complex was detected in the dexamethasone-labeled liver cytosol, while only one form which binds only to nuclei was found in the liver cytosol labeled with antiglucocorticoid, cortexolone. The significant amount of receptor complex which binds to DNA and nuclei was not present in the cytosol from the ventral prostate preincubated with 3H-dihydrotestosterone. (+info)