Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The adrenal cortical 'hybrid' steroids 18-oxocortisol (18-OF) and 18-hydroxycortisol (18-OHF) are elevated in patients with typical angiotensin-unresponsive aldosterone-producing adenoma (AII-unresponsive APA) and fall to normal following surgical removal of the adrenal containing the tumour. Since 18-OF was six times the upper limit of normal pre-operatively, the tumour was the site of overproduction of hybrid steroids. 2. The failure of angiotensin-responsive APA to overproduce the hybrid steroids may be linked to their more 'normal' production of cortisol, which falls significantly on removal of the tumours. 3. Hybrid steroid levels were also normal in patients with idiopathic hyperplasia of the adrenals (IHA) and in low renin essential hypertension. 4. In AII-responsive APA, glucocorticoid-suppressible hyperaldosteronism (GSH) and IHA, the hybrid steroids showed brisk responses to stimulation by ACTH and suppression by dexamethasone of endogenous ACTH. 5. Long-term suppression by dexamethasone of hybrid steroids in GSH is consistent with ACTH dependence, rather than angiotensin dependence. 6. Studies of the regulation of hybrid steroid secretion in various categories of hypertension will further define the biosynthetic distinctiveness which is already useful diagnostically.
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PMID:Adrenal transitional zone steroids, 18-oxo and 18-hydroxycortisol, useful in the diagnosis of primary aldosteronism, are ACTH-dependent. 285 57

200 patients with mineralocorticoid hypertension were studied at the Clinical Study Center. The study of 150 patients with primary aldosteronism revealed five distinct subsets based on their responses to the upright posture, after administration of intravenous saline, deoxycorticosterone acetate, and spironolactone. Two new types were identified--aldosterone producing responsive adenoma (AP-RA) and primary adrenal hyperplasia (PAH). Patients with AP-RA maintained normal physiologic responses to the above maneuvers. Patients with PAH had responses similar to patients with an aldosterone producing adenoma (APA) but no tumor was identified. Both types were cured by unilateral adrenalectomy. There has been no change in subtype in up to 20 years of follow-up. The notion of a continuum from low renin hypertension to APA is not supported. Primary deoxycorticosteronism caused by a benign adrenal adenoma, malignancy and hyperplasia is described. Uniquely, overproduction of the 17-deoxysteroids of the zona fasciculata occurs with normal 17-hydroxy function. After the removal of a benign adenoma the contralateral adrenal gland revealed a delay in the 17-deoxysteroid responses to ACTH in the face of normal cortisol increases. This suggests that an independent pituitary regulator of the 17-deoxypathway may exist. Other hypertensive disorders with excessive deoxycorticosterone production are linked with increases of ACTH and cortisol levels. The hallmarks of primary deoxycorticosteronism are hypertension with hypokalemia, suppression of renin and aldosterone, and overproduction of the 17-deoxysteroids.
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PMID:Identification and implications of new types of mineralocorticoid hypertension. 291 10

The withdrawal effect of spironolactone treatment on natriuresis was studied in relation to atrial natriuretic peptide (ANP) in five patients with primary aldosteronism due to adenoma. The patients had been treated with spironolactone for 2-3 months before they were admitted. After admission, blood pressure, body weight, and urinary excretion of sodium were measured daily. Venous samples were obtained twice a week for measurements of plasma levels of ANP, plasma renin activity (PRA), and plasma concentrations of aldosterone (PAC), cortisol, and deoxycorticosterone. The study was performed for 7 days during the treatment with spironolactone and for 18 days after stopping the administration. Plasma volume was determined two times, during the control period and on the 13th day after stopping spironolactone. Urinary sodium excretion decreased initially and returned to the control levels successively. Body weight and plasma volume increased, and blood pressure rose steadily. PRA and the plasma concentrations of cortisol and deoxycorticosterone decreased significantly (P less than 0.05); however, high levels of PAC did not alter significantly. Plasma ANP levels increased significantly (P less than 0.05) from 26 +/- 4 pg/ml during the control period to 195 +/- 47 pg/ml on the 13th day after stopping spironolactone. The data of the urinary sodium excretion showed the escape from sodium-retaining effect of aldosterone, and this escape could be explained by the increase in plasma ANP. Furthermore, ANP might contribute to the decrease in cortisol and deoxycorticosterone in plasma because of the direct inhibitory action of ANP on steroidogenesis.
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PMID:Role of atrial natriuretic peptide in mineralocorticoid escape phenomenon in patients with primary aldosteronism. 295 9

Low-dose angiotensin II (ANG II) infusion raised plasma atrial natriuretic peptide (ANP) levels only when endogenous renin-angiotensin levels were low, as in aldosterone-producing adenoma. When plasma renin activity (PRA) levels rose tenfold following removal of the tumour, low-dose ANG II infusion no longer stimulated ANP, but fivefold higher doses did. Indomethacin lowered both PRA and ANP in Bartter's syndrome and in normal subjects. The effect of indomethacin on ANP is probably not direct, since it did not lower ANP in aldosterone-producing adenoma. Neither did it lower PRA in aldosterone-producing adenoma, and in most studies ANP and PRA moved in parallel, consistent with positive regulation of ANP by ANG II. When ANG II infusion stimulated ANP, it also raised blood pressure, which could therefore be mediating the effects of ANG II on ANP. However, both PRA and ANP are high in Bartter's syndrome, while blood pressure is normal or low, and indomethacin lowers PRA and ANP in Bartter's syndrome and in normal subjects without lowering the blood pressure. The relative importance of regulatory factors such as central blood volume/atrial pressure and ANG II level probably varies in different situations. In aldosterone-producing adenoma, a high central blood volume appears to over-ride the effect of a low ANG II level. In Bartter's syndrome a high ANG II level appears to over-ride the effect of low central blood volume.
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PMID:Atrial natriuretic peptide levels during angiotensin infusion and indomethacin administration are consistent with angiotensin-mediated regulation in man. 296 35

Excess production of proopiomelanocortin (POMC)-derived peptides with aldosterone-stimulating activity has been suggested to play a pathogenetic role in idiopathic hyperaldosteronism (IHA). To further investigate this issue, the opiate receptor antagonist naloxone was administered to 14 patients with primary aldosteronism, 6 with an aldosterone-producing adenoma (APA) and 8 with IHA. Clinical and hormonal effects of iv administration of naloxone (10 mg as a bolus) were compared with those obtained in 8 normal subjects. In normals as well as in APA and IHA patients, naloxone caused a significant increase in plasma cortisol, and no change in ACTH, plasma renin activity (PRA) and aldosterone levels. All subjects were retested after 2 mg dexamethasone. ACTH and cortisol were reduced and PRA was unchanged in all groups, without modifications after naloxone. Baseline aldosterone showed no significant changes in all groups. While normal subjects and APA failed to show any aldosterone response to naloxone after dexamethasone, IHA patients demonstrated a significant decrease. beta-endorphin concentrations were in the normal range before and after dexamethasone. In conclusion, naloxone may have a direct action upon adrenal zona fasciculata increasing the cortisol responsiveness to physiological levels of ACTH in either normals or APA and IHA patients. The decrease of aldosterone induced by naloxone in IHA may be due to an intraadrenal opioid control of zona glomerulosa in this disorder.
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PMID:Effects of naloxone on adrenal cortex regulation in patients with primary aldosteronism. 297 May

1. Plasma atrial natriuretic peptide (ANP) levels were positively correlated with plasma renin activity (PRA) levels, when blood volume and blood pressure (BP) were not raised in normal subjects (NLS) or patients with postoperative aldosterone-producing adenoma (APA), Bartter's syndrome (BS), Addison's disease, anorexia nervosa, diuretic abuse or salt-losing congenital adrenal hyperplasia. 2. Angiotensin II infusion raised ANP levels in NLS, and patients with BS, pre- and postoperative APA, only when BP rose, suggesting that this effect might be mediated by the rise in BP. 3. Captopril lowered aldosterone and ANP levels in renal artery stenosis, but falling BP levels could mediate this effect. Captopril lowered aldosterone and BP in BS, but did not lower ANP, perhaps because angiotensin remained elevated. 4. Indomethacin lowered ANP when PRA was initially normal or raised (NLS and BS), but not when PRA was suppressed (APA). This effect could not be mediated by BP, which rose, but could be mediated by renin-angiotensin, which fell. 5. Factors other than central blood volume and atrial stretch may modulate ANP levels. Plasma angiotensin II may be such a factor, and may exert an important influence at high levels, especially when blood volume is low.
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PMID:Altering angiotensin levels by administration of captopril or indomethacin, or by angiotensin infusion, contributes to an understanding of atrial natriuretic peptide regulation in man. 297 45

The practicability and tolerability of trilostane, a competitive inhibitor of 3 beta-hydroxysteroid-delta 5-dehydrogenase, for the therapy of primary aldosteronism was assessed in 1 patient with aldosterone-producing adenoma (APA) and 3 subjects with idiopathic adrenal hyperplasia (IHA). Trilostane afforded reduction of plasma levels of aldosterone, progesterone, deoxycorticosterone, 17-OH progesterone, cortisol, delta 4-androstenedione, and urinary excretion of 17-hydroxycorticosteroid. Conversely, circulating levels of dehydroepiandrosterone, dehydroepiandrosterone sulfate, and urinary excretion of 17-ketosteroids were increased following this drug therapy. Suppression of mineralo- or glucocorticoid biosynthesis was accompanied by an increase in plasma renin activity. One patient with APA or 3 subjects with IHA showed slight or remarkable improvement of hypertension and hypokalemia. Based on these findings, efficacy and tolerability of trilostane appear to aid in the treatment of IHA.
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PMID:Primary aldosteronism treated by trilostane (3 beta-hydroxysteroid dehydrogenase inhibitor). 298 27

Serotonin stimulates aldosterone secretion both in vitro and in vivo, and serotonin antagonism decreases plasma aldosterone levels in patients with idiopathic aldosteronism. This study was designed to assess the effects of the serotonin precursor, 5-hydroxytryptophan (5HTP), upon aldosterone secretion in man, and to determine whether stimulatory effects of 5HTP are mediated through the central nervous system. Oral 5HTP, administered as a single 200-mg dose, increased plasma aldosterone levels from 4.7 +/- 0.6 to 13.3 +/- 2.8 ng/dl in dexamethasone-pretreated, normal volunteers. Peripheral inhibition of decarboxylation of 5HTP, achieved by pretreatment with carboxydopa, 25 mg three times daily for 3 d, significantly increased the stimulatory effects of 5HTP on aldosterone levels (P less than 0.001). No change in aldosterone levels occurred in subjects who received placebo after pretreatment with dexamethasone and carboxydopa. Increased aldosterone was not accompanied by increases in plasma levels of renin activity, potassium, or ACTH. Plasma levels of 5HTP were markedly increased by carboxydopa pretreatment, but peak plasma levels of serotonin were not significantly altered. Four patients with idiopathic aldosteronism all had an increase in plasma aldosterone levels after 5HTP administration, whereas the response in four patients with aldosterone-producing adenoma was variable. Incubation of isolated human and rat adrenal glomerulosa cells with serotonin resulted in increased aldosterone secretion by both sets of cells, whereas 5HTP was ineffective in stimulating aldosterone secretion in vitro. We conclude that central serotonergic pathways are involved in the stimulation of aldosterone induced by administration of 5HTP. This mechanism may be an important etiologic factor in the hypersecretion of aldosterone that occurs in patients with idiopathic aldosteronism.
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PMID:Central serotonergic stimulation of aldosterone secretion. 299 80

An enzyme immunoassay for serum 18-hydroxycorticosterone was established using alkaline phosphatase as a label. The antiserum for 18-hydroxycorticosterone was produced by immunization of rabbits with 18-hydroxycorticosterone 3-(o-carboxymethyl) oxime conjugated to bovine serum albumin. Sephadex LH-20 column chromatography was used to separate 18-hydroxycorticosterone from other steroids in serum samples. The minimal detectable amount of 18-hydroxycorticosterone was 50 pg/tube, and the measurable range was from 5 to 1000 ng/dl when a 1.0 ml serum sample was used. Intra- and inter-assay coefficients of variance were 5.0% (n = 6), and 5.8% (n = 6), respectively. In normal controls the serum 18-hydroxycorticosterone level was 4.8 approximately 34.0 ng/dl (mean +/- S.D. = 17.1 +/- 9.0 ng/dl) on an unrestricted diet. Seven out of 8 patients with aldosterone-producing adenoma had above-normal serum 18-hydroxycorticosterone levels. Serum 18-hydroxycorticosterone increased and decreased significantly following ACTH and dexamethasone administration, respectively. In essential hypertensive patients, serum 18-hydroxycorticosterone was high during a low-sodium diet and was suppressed remarkably by captopril. These observations support the previous reports that adrenal 18-hydroxycorticosterone synthesis is dependent on both ACTH and the renin-angiotensin system. The present method is sufficiently sensitive and producible, avoids the use of radioisotopes and is quite satisfactory for clinical use.
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PMID:[Enzyme immunoassay for serum 18-hydroxycorticosterone and its clinical application]. 300 75

Renin, angiotensinogen, and converting enzyme were detected in 10 normal human pituitary glands by immunohistochemical techniques. Renin was stained by polyclonal and monoclonal antibodies directed against human renin, and an antibody directed against the renin prosegment revealed the presence of prorenin. Immunoreactive angiotensinogen and angiotensin I-converting enzyme were found in the same cells as renin. Using serial sections and double immunohistochemical labeling with a PRL antiserum, all of the proteins of the renin-angiotensin system appeared to be localized within the lactotroph cells, and no component of the renin system was detected in any of the other pituitary cells. Renin, angiotensinogen, and angiotensin I-converting enzyme also were found in 6 PRL-secreting adenomas as well as in a mixed PRL/GH-secreting adenoma. The renin content of a PRL adenoma was about 1/100th that of a normal kidney. Renin activity could be blocked by an anticatalytic human renin antibody. No renin, angioten-sinogen, or angiotensin I-converting enzyme was found in 6 GH-secreting adenomas, 1 corticotroph adenoma, or 10 nonsecreting pituitary adenomas. The colocalization of proteins of the renin-angiotensin system suggests production of angiotensin II within the lactotroph cells and favors the hypothesis of a paracrine action of this peptide.
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PMID:Presence of renin, angiotensinogen, and converting enzyme in human pituitary lactotroph cells and prolactin adenomas. 301 40


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