Showing papers on "Adrenal cortex published in 1990"

Immunohistochemical localization of androgen receptors with mono- and polyclonal antibodies to androgen receptor.

Abstract: Rat, human, and mouse tissues were stained immunohistochemically using mono- and polyclonal androgen receptor antibodies. Monoclonal antibodies were raised in rats and used to stain human and mouse tissues; polyclonal antibodies were raised in rabbits and used to stain rat tissues. Frozen tissue sections were incubated with the appropriate androgen receptor antibody and staining was completed by the indirect avidin-biotin peroxidase method. A comprehensive survey of rat and mouse tissues was performed. Antibody staining was found exclusively in the nucleus of certain specific cell types, suggesting that the androgen receptor is a nuclear protein. All male sexual organs in the rat showed strong positive nuclear staining for androgen receptor. Weaker positive reactions were seen in kidney, liver, adrenal cortex and pituitary gland. Furthermore, positive staining for androgen receptor was exhibited in skeletal, cardiac and smooth muscle cells, and central nervous tissue. Female reproductive organs also contained androgen receptor-positive cells. The spleen was found to be the only organ examined which did not stain for androgen receptor. The monoclonal antibody could also demonstrate androgen receptor-positive cells in a human prostatic cancer and in a prostate with benign hyperplasia. These data demonstrate the use of antibodies in revealing cellular/subcellular distribution of androgen receptor in target tissues.

Regulation of the primate fetal adrenal cortex.

Abstract: I. Physiological Significance of the Fetal Adrenal IN MOST mammalian species, products of the fetal adrenal gland appear to play an important role in regulating maturation of various organ systems in the fetus (1–5), providing the fetus homeostatic mechanisms to respond to stress (6), and initiating and/or participating in the cascade of events culminating in the birth of a newborn (7–9). Thus, cortisol, presumably of fetal adrenal origin, is one of the chemical messengers involved in the stimuli to lung maturation (3,4), deposition of glycogen in the liver (10, 11), and induction of several enzymes in the fetal brain, retina, pancreas, and gastrointestinal tract (12–17) that normally are associated with late intrauterine life. It is well known, from the elegant work of Liggins and colleagues (7), that ablation of the fetal adrenal in sheep prevents parturition, whereas infusion of cortisol or ACTH1 to the fetus induces premature delivery. Although evidence that the fetal adrenal of the human or nonhuman ...

Association of the GTP-binding protein Rab3A with bovine adrenal chromaffin granules.

Abstract: The Rab3A protein belongs to a large family of small GTP-binding proteins that are present in eukaryotic cells and that share amino acid identities with the Ras proteins (products of the ras protooncogenes) Rab3A, which is specifically located in nervous and endocrine tissues, is suspected to play a key role in secretion Its localization was investigated in bovine adrenal gland by using a polyclonal antibody Rab3A was detected in adrenal medulla but not in adrenal cortex In cultured adrenal medulla cells Rab3A was specifically expressed in the catecholamine-secreting chromaffin cells Subcellular fractionation suggested that Rab3A is about 30% cytosolic and that particulate Rab3A is associated with the membrane of chromaffin granules (the catecholamine storage organelles) and with a second compartment likely to be the plasma membrane The Rab3A localization on chromaffin granule membranes was confirmed by immunoadsorption with an antibody against dopamine beta-hydroxylase Rab3A was not extracted from this membrane by NaCl or KBr but was partially extracted by urea and totally solubilized by Triton X-100, suggesting either an interaction with an intrinsic protein or a membrane association through fatty acid acylation This study suggests that Rab3A, which may also be located on other secretory vesicles containing noncharacterized small GTP-binding proteins, is involved in their biogenesis or in the regulated secretion process

Circadian variations in plasma levels of hypophyseal, adrenocortical and testicular hormones in men infected with human immunodeficiency virus.

Abstract: Alterations in the circadian time structure of the secretion of several hormones were investigated in 13 male patients infected with human immunodeficiency virus (HIV). Seven were asymptomatic (classified CDC II, according to the criteria of the Atlanta Centers for Disease Control), and 6 had acquired immunodeficiency syndrome (CDC IV). Ten healthy males volunteered as controls. Plasma levels of dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S), cortisol, testosterone, ACTH, and beta-endorphin were determined by RIA in blood samples obtained every 4 h from 0830-0830 h the next morning. Data were analyzed both by two-way analysis of variance and the cosinor method. Circadian rhythms were statistically validated for each of the six hormones in each of the three groups of subjects. Compared with the control subjects, mesors (24-h adjusted means) were significantly higher for cortisol and lower for DHEA, DHEA-S, and ACTH (P less than 0.001 for all four hormones) in all HIV-infected patients. Plasma testosterone mesors were similar in controls and CDC II patients, but decreased significantly in the CDC IV patient group (P less than 0.05). Analysis of the circadian rhythms of plasma hormone levels clearly indicated an altered adrenal hormonal state in HIV-infected male patients, even during the asymptomatic period of the infection. For instance, plasma cortisol at 0430 h was more than twice as high in HIV-infected patients as it was in time-qualified controls. Although patients already had elevated plasma cortisol and lowered adrenal androgen levels at this stage, hypogonadism was not observed, as gauged by plasma testosterone concentrations. We speculate that the primary hormonal defect in HIV-infected patients is increased cortisol secretion resulting from circadian-varying stimulation of the adrenal cortex by a factor other than pituitary ACTH. This factor might be a stimulating substance secreted primarily by infected immune cells. Excess cortisol would lower adrenal androgen secretion by shifting adrenal steroid biosynthesis toward glucocorticoids and decreasing pituitary ACTH secretion via a negative feedback mechanism.

3β-Hydroxysteroid Dehydrogenase/Isomerase in the Fetal Zone and Neocortex of the Human Fetal Adrenal Gland

Abstract: The fetal zone of the human fetal adrenal (HFA) gland is established to have decreased 3 beta-hydroxysteroid dehydrogenase/delta 4-5 isomerase (3 beta HSD) activity compared to the neocortex or definitive zone. 3 beta HSD activity, however, can be induced in primary cell culture through treatment with ACTH. Therefore, the HFA with two distinct steroidogenic zones with differences in 3 beta HSD activity as well as the capacity to increase 3 beta HSD activity in response to ACTH provides an excellent model to study the regulation of this enzyme. The presence of 3 beta HSD in the fetal and neocortex zones of the HFA was examined using a polyclonal antibody raised against purified human placental microsomal 3 beta HSD. After homogenates of the fetal and neocortical zones of the HFA were electrophoresed on a sodium dodecyl sulfate-polyacrylamide gel and immunoblotted, the presence of the 3 beta HSD protein with a molecular size of 45 kDa could be demonstrated only in the neocortical zone. ACTH treatment (greater than 2 days) of fetal and neocortical zone explant cultures produced increases in cortisol secretion associated with the respective levels of immunodetectable 3 beta HSD protein. Cortisol and dehydroepiandrosterone sulfate were the respective principal steroid products of neocortical and fetal zone explants. After ACTH treatment, immunodetectable 3 beta HSD was induced to a greater magnitude in the neocortex. These findings provide evidence that the lack of 3 beta HSD activity in the fetal zone, previously considered to be the result of the presence of an endogenous inhibitor, is due to an absence of the protein in this portion of the gland. The lack or minimal expression of 3 beta HSD in the fetal zone of HFA may be due to the action (or lack thereof) of a tissue-specific factor regulating the synthesis of 3 beta HSD.

Effects of splanchnic nerve stimulation on the adrenal cortex may be mediated by chromaffin cells in a paracrine manner

Abstract: The effects of nerve activation and of the catecholamines epinephrine and norepinephrine on adrenal corticosteroid release were investigated in intact isolated perfused pig adrenals with preserved nerve supply. To study the contact zones of medullary and cortical tissues, porcine adrenals were examined on the histological and ultrastructural levels. Splanchnic nerve activation stimulated in parallel the release of epinephrine (from a basal value of 0.31 +/- 0.11 to 8.13 +/- 0.60 microgram/min) and norepinephrine (from 0.76 +/- 0.68 to 12.94 +/- 3.58 micrograms/min) and the release of the corticosteroids cortisol (from 0.62 +/- 0.19 to 2.00 +/- 0.35 micrograms/min) and aldosterone (from 3.34 +/- 0.59 to 7.53 +/- 1.63 ng sigma in). Also, perfusion of the isolated adrenals with catecholamines provoked a significant release of the corticosteroids. Epinephrine (10(-6) M) stimulated the release of cortisol (from 0.59 +/- 0.31 to 2.66 +/- 0.34 micrograms/min) and aldosterone (from 2.12 +/- 0.42 to 4.68 +/- 0.92 ng/min). Norepinephrine (10(-6) M) stimulated the release of cortisol (from 0.26 +/- 0.07 to 1.28 +/- 0.10 micrograms/min) and aldosterone (from 1.28 +/- 0.37 to 3.57 +/- 0.80 ng/min). Using an immunostaining for synaptophysin, which is specific for neuroendocrine cells, chromaffin cells could be detected within all three zones of the adrenal cortex. The two endocrine tissues appear to be closely interwoven. On the ultrastructural level, medullary cells are in apposition to cortical cells, with close cellular contacts. These results show that the release of corticosteroids cortisol and aldosterone can be stimulated through the sympatho-adrenal system. Taking into consideration the close colocalization of cortical and medullary tissues, this stimulation may be mediated by chromaffin cells in a paracrine manner.

Low density lipoprotein receptor-binding activity in human tissues : quantitative importance of hepatic receptors and evidence for regulation of their expression in vivo

Abstract: The heparin-sensitive binding of 125I-labeled low-density lipoprotein (LDL) to homogenates from 18 different normal human tissues and some solid tumors was determined. The binding to adrenal and liver homogenates fulfilled criteria established for the binding of LDL to its receptor--namely, (i) saturability, (ii) sensitivity to proteolytic destruction, (iii) inhibition by EDTA, and (iv) heat sensitivity. When the binding of 125I-labeled LDL was assayed at a constant concentration (50 micrograms/ml), the adrenal gland and the ovary had the highest binding of normal tissues. The highest binding per g of tissue overall was obtained in homogenates of a gastric carcinoma and a parotid adenoma. When the weights of the parenchymatous organs were considered, the major amount of LDL receptors was contained in the liver. To study the possible regulation of hepatic LDL-receptor expression, 11 patients were pretreated with cholestyramine (8 g twice a day for 3 weeks). Increased binding activity (+105%, P less than 0.001) was obtained in homogenates from liver biopsies from the cholestyramine-treated patients as compared with 12 untreated controls. It is concluded that the liver is the most important organ for LDL catabolism in humans and that the receptor activity in this organ can be regulated upon pharmacologic intervention. Further studies are needed to confirm the possibility that certain solid tumors can exhibit high numbers of LDL receptors.

Sex differences in adrenocortical structure and function. XXVII. The effect of ether stress on ACTH and corticosterone in intact, gonadectomized, and testosterone- or estradiol-replaced rats.

Abstract: Studies were performed on the reactivity of the hypothalamo-pituitary-adrenocortical axis of intact, gonadectomized, and testosterone- or estradiol-replaced rats to standard ether stress. Plasma ACTH and corticosterone (B) levels, anterior pituitary ACTH, and adrenal B content were estimated 20 and 40 min after stress application and in unstressed animals. Ether stress resulted in an increase in plasma ACTH and B levels and in adrenal B content while pituitary ACTH content was notably lower when compared with unstressed rats. The response was markedly higher in female than in male rats. After orchiectomy and testosterone replacement, plasma ACTH and B responses to ether stress were similar to those observed in intact male rats. On the other hand, ovariectomized females responded to ether stress like intact males, while after estradiol replacement the pattern of plasma ACTH and B concentration and adrenal B content was similar to that in intact female rats. Thus, the higher responsiveness of the pituitary-adrenal cortex axis of female rats to ether stress depends on stimulatory or facilitatory effect of estradiol.

Pathogenesis of the type 2 variant of the syndrome of apparent mineralocorticoid excess.

Abstract: The syndrome of apparent mineralocorticoid excess, which is not a primary disorder of the adrenal cortex, describes the association of an unexplained hypermineralocorticoid state with a decreased rate of peripheral 11 beta-hydroxydehydrogenation of cortisol to cortisone. Studies in this syndrome have led to the hypothesis that peripheral cortisol inactivation is the normal mechanism permitting specific mineralocorticoid recognition. This view reconciled developing evidence that the mineralocorticoid receptor itself could not distinguish between mineralocorticoids and glucocorticoids. The syndrome occurs in two forms. In both forms there is decreased turnover of a normal level of plasma cortisol, consistent with the view that delayed removal of the glucocorticoid from strategic receptor sites unmasks its potential mineralocorticoid agonism. In the type 1 variant, impaired 11 beta-hydroxydehydrogenation is reflected by an elevated cortisol/cortisone metabolite ratio. In three patients with the type 2 variant, this ratio was normal, suggesting that the rate of 11 beta-hydroxydehydrogenation was unimpaired. The hypertension and hypokalemic alkalosis of both forms are improved by spironolactone, but patients with the type 2 variant have responded somewhat better to the suppression of cortisol by dexamethasone.

A Stimulatory Effect of Interleukin-1 on Adrenocortical Cortisol Secretion Mediated by Prostaglandins*

Abstract: Studies using cultured bovine adrenocortical cells now demonstrate that the cytokines interleukin-1 (IL-1) alpha and beta, contrary to previous reports, can stimulate cortisol secretion in vitro in a dose- and time-dependent fashion. However detectable levels of IL-1 receptor could not be demonstrated in adrenal cortical, medullary, or capsular cells by membrane displacement of iodinated IL-1 alpha by unlabeled IL-1 beta, a technique that readily demonstrates specific IL-1 alpha-binding sites on 3T3 fibroblasts. The stimulatory effect of IL-1 on cortisol secretion could be totally blocked by indomethacin, an indication that this effect might be mediated indirectly via local release of prostaglandins (PGs). Subsequent investigations have confirmed that IL-1 does enhance the conversion of [3H]arachidonate to PGs by cultured adrenal cells, and that some of these PGs (PGD2, PGF2 alpha, and PGE2), in turn, can stimulate cortisol production. Taken together these observations suggest that IL-1-induced stimulation of cortisol secretion is mediated through local release of PGs by a small subpopulation of cells within the adrenal gland.

cis modification of the steroid 21-hydroxylase gene prevents its expression in the Y1 mouse adrenocortical tumor cell line.

Abstract: The Y1 mouse adrenocortical tumor cell line retains the ability to synthesize and secrete steroids, but does not express steroid 21-hydroxylase (C21) and, therefore, does not produce 21-hydroxylated steroids. In this investigation the mechanisms underlying the loss of C21 activity in the Y1 cell line were explored. A 9-kilobase Bg/ll fragment containing the C21 gene was cloned from the Y1 genome. This genomic clone directed the synthesis of C21 transcripts and 21-hydroxylated steroid products when transfected back into the Y1 cell line. As determined by restriction endonuclease digestions with Mspl and Hpall, enzymes that distinguish between unmethylated and methylated CCGG sites, the endogenous C21 gene was extensively methylated in Y1 adrenal cells and in cells from other mouse tissues that do not normally express this gene. In contrast, the C21 gene was hypomethylated in primary cultures of mouse adrenal cells which normally synthesize large amounts of C21. The cloned C21 gene transfected into Y1 cells...

Evidence for central and peripheral serotonergic control of corticosterone secretion in the conscious rat.

Abstract: Serotonin (5-HT) and 5-HT agonists act on multiple 5-HT receptor subtypes to increase corticosterone secretion. The present experiments describe the effects of a highly selective 5-HT2 receptor agonist DOI [(+-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane HCl] on plasma corticosterone in conscious, unrestrained, male rats with indwelling arterial and venous catheters. DOI (500 micrograms/kg, i.v.) increased plasma corticosterone levels 6- to 7-fold from 15 to 60 min. Pretreatment with the central 5-HT2 antagonist LY 53857 (100 micrograms/kg, i.v.) blocked the effect of DOI on corticosterone secretion at all times. The peripheral 5-HT2 antagonist xylamidine (100 micrograms/kg, i.v.) attenuated the corticosterone response elicited 15 min after DOI but did not alter the 60-min response. In contrast, dexamethasone pretreatment (350 micrograms/kg, s.c.) attenuated the corticosterone response to DOI at 15 min, but abolished the response at 60 min. The increase in corticosterone levels elicited 5 min after the nonselective 5-HT agonist quipazine (3 mg/kg, i.v.) was also reduced by xylamidine. These data suggest that 5-HT2 receptor agonists increase corticosterone secretion initially, in part, through a direct adrenal mechanism not entirely dependent on adrenocorticotropin, and at later times via a central, dexamethasone-suppressible mechanism. This raises the possibility that endogenous 5-HT in the adrenal medulla may act as a local paracrine to participate in the regulation of corticosterone secretion from the adrenal cortex.

Toxic effect of heavy metals on cells isolated from the rat adrenal and testis.

Abstract: Heavy metals including mercury, cadmium, cobalt, and copper (100 microM) exerted an adverse effect on the viability of isolated rat adrenal capsular (zona glomerulosa), adrenal decapsular (fasciculata and reticularis), and Leydig cells of the testis, with mercury being the most potent. Due to the decreased cell viability there was a parallel reduction in corticotropin-stimulated corticosterone production by adrenal decapsular cells and luteinizing hormone-stimulated testosterone production by Leydig cells. The results indicated a direct toxic action of these heavy metals on steroid-producing cells in the adrenal gland and the testis. Other metals tested, including lead, zinc, aluminum, chromium, iron, nickel, and lithium, did not exert any deleterious effect on cell viability or hormone-induced steroidogenesis in adrenal and Leydig cells when tested up to a concentration of 100 microM.

Basic fibroblast growth factor (bFGF) immunoreactivity is present in chromaffin granules.

Abstract: Basic fibroblast growth factor (bFGF) has recently been isolated from bovine adrenal glands. Immunohistological data revealed its presence in both adrenal cortex and adrenal medulla. Using immuno-electronmicroscopy, we found that in medullary chromaffin cells bFGF-immunoreactivity is localized in the secretory granules. Immunoreactivity also was observed by electronmicroscopy in isolated granules. Western blot analysis revealed the presence of the typical 18-kDa bFGF and additional immunoreactive materials with molecular masses of approximately 24, 30, and 46 kDa in whole bovine adrenal, and in cortex and medulla. Similar results were obtained with proteins from bovine chromaffin granules, with the following two exceptions: the 46-kDa immunoreactivity was found to be highly enriched when compared with medulla or cortex, and the 18-kDa band could be detected with only an antiserum against a synthetic peptide comprising the 24 NH2-terminal amino acids of bFGF, and not with an antiserum against purified bovine pituitary bFGF. All fractions enriched for bFGF-immunoreactivity showed neurotrophic activity for chick ciliary ganglion neurons, which could be blocked by antibodies. These results demonstrate for the first time the localization and occurrence of bFGF in a cellular secretory organelle, and present further evidence for the existence of higher molecular weight immunoreactive forms of bFGF.

Androgens delay human fetal lung maturation in vitro.

Abstract: The mature lung produces pulmonary surfactant, a lipid-protein complex that prevents lung alveoli from becoming atelectatic. The prenatal surge of surfactant production in preparation for birth occurs between 28-34 weeks gestation and is triggered by glucocorticoids, which stimulate surfactant synthesis by alveolar epithelial cells through a series of biochemical steps mediated by mesenchymal-epithelial interactions. In contrast to this, when explanted midgestation human fetal lung tissue is maintained in serum-free medium, there is a spontaneous increase (40%) in de novo saturated phosphatidylcholine (SPC) synthesis on the fifth day in culture. Addition of dexamethasone (DEX; 1 x 10(-8) M) to the culture medium causes the increased synthesis in SPC to occur earlier (day 4) and to a greater extent (87%). Addition of an equimolar concentration of dihydrotestosterone (DHT) to the medium delays both the spontaneous and DEX-stimulated increases in SPC synthesis by 24 h. Weak fetal adrenal androgens are also able to block both spontaneous and DEX-stimulated SPC synthesis. Addition of DHT to the explant cultures at daily intervals reveals that inhibition of the DEX effect occurs within the first 24 h after exposure. The antiandrogen flutamide neutralizes the effect of DHT, indicating that it acts through the androgen receptor to block the glucocorticoid. Therefore, the human fetal adrenal cortex may time lung development through both inhibitory and stimulatory mechanisms.

Steroid profile in urine : a useful tool in the diagnosis and follow up of adrenocortical carcinoma

Abstract: The urinary steroid profile was determined in 24 patients with adrenocortical carcinoma. Seventeen of the patients had Cushing's syndrome, virilization or feminization, and 7 had no signs of endocrine disease. Seven of the 11 patients still alive are free of disease, after a follow-up period of 5-75 months. The steroid profile varied widely between the patients with adrenocortical carcinoma. Patients with Cushing's syndrome had increased levels of cortisol metabolites and those with virilism had raised excretion of androgen metabolites. Six of the patients with adrenocortical carcinoma showed normal values of these metabolites. In 23 of the 24 patients the excretion of 3 beta-hydroxy-5-ene steroids and/or metabolites of cortisol precursors, such as tetrahydro-11-deoxycortisol, were significantly increased, compared with healthy controls or patients with adrenal adenomas. These findings suggest a relative deficit or low activity of 3 beta-hydroxysteroid dehydrogenase/delta isomerase and/or 11 beta-hydroxylase in tumour tissue. In the single patient where the steroid profile failed to indicate malignancy, hypercortisolism was seen and the tumour mass was small. The steroid excretion normalized after radical surgery and decreased in patients responding to chemotherapy. During recurred disease the metabolites of 3 beta-hydroxy-5-ene steroids and/or cortisol precursors increased, but in some patients the excretory pattern then was different from that seen before treatment.

Changes in the hypothalamo-pituitary-adrenal axis of genetically obese fa/fa rats: a structural, immunocytochemical, and morphometrical study.

Abstract: Most metabolic disorders of genetically obese Zucker rats are reversed by adrenalectomy and are restored by corticosterone treatment, thus suggesting that a functional hypercorticosteronemic state is involved in the pathogenesis of the obesity syndrome in fa/fa rats. However, the hormone content and morphology of the hypothalamo-pituitary-adrenal axis of this animal model have to our knowledge not yet been described. We, thus, investigated morphologically and morphometrically the hypothalamic regions involved in CRF synthesis and secretion in male fa/fa rats. To ascertain if the brain is selectively or uniformly affected, we studied the main nuclei of the lateral and mediobasal hypothalamus, i.e. arcuate, lateral hypothalamic, and ventromedial nucleus and the parvicellular portion of the paraventricular nucleus. Moreover, after immunocytochemical labeling, we analyzed densitometrically the CRF-bearing axons of the median eminence and the ACTH-containing cells of the anterior and intermediate lobe of the pituitary gland. Finally, we investigated the adrenal glands by qualitative light microscopy. In fa/fa rats most hypothalamic nuclei were structurally changed. Furthermore, hypothalamic CRF and anterior pituitary ACTH contents as well as adrenal weight were increased, the zona fasciculata of the adrenal cortex was hypertrophic, and the ACTH content of the intermediate lobe was reduced. In conclusion, our results demonstrate that the obesity syndrome in genetically obese fa/fa rats is associated with lesions of the hypothalamo-pituitary-adrenal axis consistent with hyperadrenocorticism due to hyperactivity of the whole adrenal axis. Alterations also occur in the hypothalamic nuclei controlling glycemia, insulinemia, and circadian corticosterone secretion.

Expression and functions of P-glycoprotein (mdr1 gene product) in normal and malignant tissues.

Abstract: This paper describes the cellular and tissue distribution of P-glycoprotein (P-GP) (mdr1 gene product), the role of P-GP in vivo and immunodiagnosis of multi-drug-resistant cancers. We mainly used MRK 16 monoclonal antibody (MAb) reactive with P-GP. P-GP was found to be expressed very strongly in the adrenal cortex of adults and strongly in the renal tubules of the kidney, capillary blood vessels of the brain, and also in placenta. Interestingly, P-GP was not distributed in fetal and neonatal adrenals, and thus may be closely related to adrenal maturation. A high level of P-GP expression was also seen in all cases of functional hormone-producing adrenal tumor, one case of insulinoma, two cases of untreated colonic cancer, one case each of untreated lung cancer, gastric cancer and breast cancer, six cases of renal cell carcinoma and 17 cases of bladder cancer. Using flow cytometry and immunocytochemistry, we investigated the reactivity of MRK 16 MAb with peripheral human mononuclear cells (mainly blastic cells and lymphocytes) from 31 patients with leukemia or malignant lymphoma. Reactivity with MRK 16 MAb was observed in five cases. Some cases reflected the prior administration of adriamycin, vincristine and VP-16, which are known to induce P-GP expression. P-GP-MRK 16-protein A-Sepharose complex derived from human adrenal possessed marked ATPase activity. These data suggest that P-GP may play a physiological role in the human adrenal. Finally, diagnostic criteria of multi-drug-resistant cancers are presented.

Immunolocalization of 3β-hydroxysteroid dehydrogenase in human adrenal cortex and in its disorders.

Abstract: Immunohistochemical localization of 3β-hydroxysteroid dehydrogenase/Δ5→4-isomerase (3β-HSD), which converts Δ5-3β-hydroxysteroids to Δ4-3-ketosteroids, was performed in the human adrenal gland and in its disorders by employing a specific antibody raised against the enzyme purified from human placenta. Immunoreactivity of 3β-HSD was present in all three cortical zones of the adrenal glands obtained at autopsy, while in surgically removed adrenal glands, immunoreactivity was dominant in the zona fasciculata (ZF), with faint immunoreactivity in the zona glomerulosa (ZG) and the zona reticularis (ZR). Intracortical localization of 3β-HSD in the adrenal glands obtained at autopsy may represent an adrenal adaptation to antemortem stress, with shifting of adrenal pregnenolone- a substrate of 3β-HSD - as well as steroid 17α-hydroxylase from adrenal androgen synthesis to glucocorticoid synthesis. In adrenocortical hyperplasia, marked immunoreactivity was observed in the ZG and outer ZF in adrenal glands with idiopathic hyperaldosteronism and in the ZF and ZR, especially in cortical micronodules, in the adrenal glands associated with Cushing's disease. In aldosteronoma and Cushing's adenoma, immunoreactivity of the enzyme was much more intense in large clear tumor cells than in small compact tumor cells. Immunolocalization of 3β-HSD can yield important information toward an understanding of adrenal steroid metabolism in both physiological and pathological processes.

Immunocytochemical mapping of basic fibroblast growth factor in the developing and adult rat adrenal gland.

Abstract: We studied the spatial and temporal pattern of basic fibroblast growth factor (bFGF) immunoreactivity in the rat adrenal gland during postnatal development. In the cortex the glomerulosa zone reveals a strong anti-bFGF immunoreactivity at all developmental ages studied. In the fasciculata zone the high number of anti-bFGF immunoreactive cells in the first week decreases during the second and third week. The late developing reticularis zone shows only few anti-bFGF labeled cells at all postnatal ages. This distributional pattern of bFGF immunoreactivity matches that of mitotic activity in the rat adrenal cortex strengthening the role of bFGF as an autocrine growth factor for adrenocortical cells. In the medulla anti-bFGF positive chromaffin cells become detectable at postnatal day (P) 8 and increase in number during the second and third week. In the adult rat the staining intensity of the chromaffin cells was higher than at P18. In the adult medulla bFGF colocalizes with noradrenaline suggesting its presence in a chromaffin cell subpopulation. In accordance with previous results the role of the chromaffin cell bFGF as a neurotrophic factor for preganglionic sympathetic neurons is discussed.

Transforming growth factor-β inhibits steroid 17α-hydroxylase cytochrome p-450 expression in ovine adrenocortical cells

Abstract: The maintenance of optimal steroidogenesis in adrenocortical cells primarily depends on the chronic action of ACTH to promote the synthesis of the various steroid-metabolizing cytochrome P-450 enzymes. In the steroidogenic pathway, 17α-hydroxylase cytochrome P-450 (P-45017α) is a key enzyme controlling the formation of cortisol and androgens. Recently, we demonstrated that transforming growth factor-β (TGFβ) is a potent inhibitor of steroid production in ovine adrenocortical cells. In the present study we used a polyclonal antibody to P450i7Q to determine adrenal cell P-45017α enzyme content by Western analysis. In addition, we used a cDNA probe encoding for bovine P-45017α mRNA to determine levels of P-45017α mRNA in sheep ovarian adrenocortical cells in primary culture. When cells were cultured in a serum-free medium in the presence of ACTH for 48 h, P-45017α activity, enzyme content, and mRNA levels for P-45017α increased by 3- to more than 10-fold. TGFβ decreased the basal level and completely blocked...

Investigations on the Morphology and Function of Adrenocortical Tissue Regenerated from Gland Capsular Fragments Autotransplanted in the Musculus Gracilis of the Rat

Abstract: This paper describes the function and morphology of regenerated adrenocortical nodules obtained by implanting, in the musculus gracilis of rats, several (n = 6-7) fragments of the capsular tissue of their excised adrenal glands. Four months after the operation, each bilaterally adrenalectomized rat developed six or seven well encapsulated adrenocortical nodules about 2-3 mm in diameter and always lacking chromaffin cells, and displayed almost complete normalization of basal and stimulated blood levels of corticosterone, but not of aldosterone. In vitro study showed that regenerated nodules were well functioning as far as glucocorticoid production was concerned. Accordingly, electron microscopy and stereology indicated that the majority of the parenchymal cells (independently of their location in the outer subcapsular, middle, or inner portions) closely resembled those of the zonae fasciculata/reticularis of the adrenal gland of age-matched sham-operated rats. By contrast, regenerated nodules evidenced a r...

Steroid hydroxylase gene expression in the ovine fetal adrenal gland following ACTH infusion

Abstract: Between 90 and 120 days of gestation (term = 147 +/- 5), when plasma cortisol concentrations in the fetus are at a minimum, levels of mRNA encoding the steroidogenic enzymes 17 alpha-hydroxylase (P-450(17 alpha] and cholesterol side-chain cleavage (P-450scc) are also very low. Over the following 30 days, P-450(17 alpha) and P-450scc gene expression increases concurrent with increasing fetal cortisol concentration. The hypothesis tested in this study was that cortisol biosynthesis is minimal in the period 90-120 days because of insufficient ACTH. Fetuses were cannulated between 98-102 days of gestation. Following recovery, 7 fetuses received 24-h ACTH infusions (12 micrograms/24 h) and 5 fetuses received 24-h vehicle infusions; 4 ACTH-infused and 4-vehicle-infused fetuses were then sacrificed immediately after cessation of the infusion. The other fetuses were left in utero for 3 days prior to sacrifice. Fetal blood samples were analysed for ACTH and cortisol and the adrenals processed for hybridization histochemistry and Northern blot analysis. ACTH, but not vehicle, induced significant increases in the width of the adrenal cortex and in the levels of P-450(17 alpha) and P-450scc mRNA. Concurrently, fetal plasma ACTH and cortisol concentrations also increased significantly. In adrenals from fetuses left in utero for 3 days after cessation of the ACTH infusion, P-450(17 alpha) and P-450scc mRNA levels returned to control levels. Plasma ACTH and cortisol levels also approximated basal values. P-450c21 mRNA levels did not vary significantly at any time with the treatments.(ABSTRACT TRUNCATED AT 250 WORDS)