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Biomedical subjects

C E Kater

Publications and source records attributed to C E Kater.

At least 37 records · Page 2Linked to original sources
PubMed1990

Continuous adrenocorticotropin administration in hypopituitarism produces asynchronous increases of deoxycorticosterone and 11-deoxycortisol relative to other reduced zona fasciculata steroids.

Short term suppression of ACTH by dexamethasone effects limited reduction in plasma deoxycorticosterone (DOC) while cortisol levels are almost completely suppressed in normal control subjects. The zona fasciculata (ZF) microsomal cytochrome P-450(21) appeared less influenced by lack of ACTH than mitochondrial cytochrome P-450(11 beta-18). Eleven patients with hypopituitarism were studied to quantitate basal ZF microsomal and mitochondrial derived steroids and their acute and extended responses to ACTH. Basal levels of 11-deoxycortisol (S) and DOC were modestly reduced (70% and 53%, respectively), while other ZF steroids were almost completely absent. Acute and prolonged ACTH treatment amplified the discrepancy in both plasma levels and production rates. DOC and S demonstrated prompt and sustained increases similar to those in normal controls, while cortisol, 18-hydroxydeoxycorticosterone, and corticosterone showed a slow subnormal recovery of steroid production. The preservation of microsomal cytochrome P-450(21) and P-450(17 alpha) to maintain DOC and S levels contrasts the reduced and delayed responses of steroids dependent on mitochondrial cytochrome P-450(11 beta-18), cortisol, corticosterone, and 18-hydroxydeoxycorticosterone. A greater effect of ACTH deficiency on mitochondrial over microsomal cytochrome P-450 activity is demonstrated, and in addition, the possibility is raised that other non-ACTH regulators sustain microsomal cytochrome P-450(21) and P-450(17 alpha) in a setting of reduced ACTH-stimulated factors.

17-Hydroxycorticosteroids↗
PubMed1989

Identification and implications of new types of mineralocorticoid hypertension.

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.

Adenoma↗
PubMed1989

The regulation of the 17-deoxy steroids in man.

One must consider the 17-DOS as a biosynthetic pathway with multiple regulatory factors. ACTH is its dominant regulator but in the absence of ACTH and in conditions where plasma renin activity is increased, this biosynthetic pathway maintains its sensitivity to exogenous ACTH. Suppression of the renin system delays the general recovery of aldosterone after the removal of an aldosterone producing adenoma but not of the 17-DOS: a pattern also showed after the removal of a DOC-producing adenoma. In addition to the possible role of the renin system there remain inexplicable situations in its regulation that cannot be explained by ACTH and renin. Our studies suggest that a non-renin, non-ACTH factor may influence the basal production of these steroids, and by its reduction, permits deviation of steroid substrate to cortisol production. This sequence may be operative in the "stress syndrome". Finally, one of the more interesting phenomenonologic patients who has been observed is a young male who has the biochemical findings and clinical signs of DOC excess with hypertension, hyperplasia, suppression of aldosterone and the RAS, and normal cortisol levels. All the 17-DOS are elevated and both adrenal veins have high concentrations. He represents excessive stimulation of this pathway by putative 17-deoxy regulator excess. The renin system is suppressed and ACTH levels are normal. Treatment with suppressive doses of glucocorticoid hormones diminishes the elevated 17-DOS and cortisol and ameliorates blood pressure. In summary, there seems to occur in clinical disorders and contrived experimental settings, suggestions that a non-renin, non-ACTH factor can regulate the 17-DOS, absence can explain some of the unusual conditions described (Fig. 1). The 17-DOS, while a vestigial pathway, may still cause disease, and provide clues to central organization of the adreno-cortical response to injury, stress, and disease.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Stimulation and suppression of the mineralocorticoid hormones in normal subjects and adrenocortical disorders.

In summary, maneuvers that affect the RAS stimulate or suppress solely aldosterone and 18-OHB and have little, if any, effect on DOC, 18-OHDOC, B, or cortisol. The magnitude of aldosterone response seems to be of equal magnitude for all stimulatory or suppressive maneuvers as used in the present protocols. Although primarily originating in the ZG, some secretion of 18-OHB from the ZF is evident by its disproportionate responses (in relation to aldosterone) to maneuvers challenging ACTH. The prompt and marked increases the 18-OHDOC and B after ACTH make them the most sensitive "markers" of the ZF steroid activity. The application of those maneuvers and MCH measurements to adrenal disorders should help to further characterize their pathophysiology.

Adolescent↗
PubMed1988

Neonatal treatment with monosodium glutamate increases plasma corticosterone in the rat.

Monosodium glutamate (MSG) has been shown to alter several neuroendocrine functions in neonatally treated rats. To evaluate for possible alterations in the hypothalamic-pituitary-adrenal axis, we injected rats during the neonatal period with MSG or saline (controls). An increase in basal plasma corticosterone levels associated with a blunted circadian variation was observed. Ether exposure produced a significant elevation in plasma corticosterone concentration in both groups of animals. However, while the increase in controls was 181.3% for male and 193.9% for female rats, in the MSG-treated rats it was only 60.7 and 31.6%, respectively. The intraperitoneal administration of high dexamethasone doses blocked corticosterone secretion in both groups. However, whereas the lowest dose (0.10 microgram/kg) suppressed corticosterone secretion in control animals, it was ineffective in MSG-treated rats. The morphological study of adrenals revealed signs of a hyperfunctional state in MSG-treated rats. These data suggest that the central lesions produced by MSG treatment disrupt the regulation of the hypothalamic-pituitary-adrenal axis.

Animals↗
PubMed1986

Spironolactone-reversible rickets associated with 11 beta-hydroxysteroid dehydrogenase deficiency syndrome.

A 7-year-old girl had growth retardation, hypertension, and hypokalemic alkalosis. Baseline serum aldosterone concentration and plasma renin activity were low and unresponsive to sodium deprivation and to orthostatic changes. Baseline serum progesterone, 17-hydroxyprogesterone, 11-deoxycortisol, and cortisol levels were normal and adequately responsive to ACTH stimulation. No steroid was found abnormally elevated. A diagnosis of 11 beta-hydroxysteroid dehydrogenase deficiency was established on the basis of elevated urinary tetrahydrocortisol plus allotetrahydrocortisol/tetrahydrocortisone ratio, determined by gas chromatography-mass spectrometry. Evaluation of bone mineral metabolism and parathyroid function, and skeletal radiographs, revealed the presence of rickets and secondary hyperparathyroidism. Treatment with spironolactone alone for 2 months corrected hypertension, hypokalemic alkalosis, and all laboratory and radiologic evidence of rickets and hyperparathyroidism, resulting in acceleration of growth rate. The response to spironolactone suggests that a hypermineralocorticoid state is responsible for the hypertensive syndrome and that rickets and hyperparathyroidism could be a consequence of excess mineralocorticoid activity.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1986

Mineralocorticoid hypertension due to hyperaldosteronism and hyperdeoxycorticosteronism.

Hypermineralocorticoid hypertension is usually due either to aldosterone or deoxycorticosterone excess. Only in hyperaldosteronism due to adenoma or primary adrenocortical hyperplasia is cure achieved by surgery. Idiopathic hyperaldosteronism may be due to different aldosterone stimulators not related to hypertension. Rare adrenocortical tumours (benign or malignant) producing hyperdeoxycorticosteronism have suppressed aldosterone and in malignancy, cortisol. They provide evidence for a separate non-adrenocorticotrophic regulator of the deoxycorticosterone pathway. The dissociation of normal or reduced cortisol from elevated deoxycorticosterone levels suggests either an adrenal enzymatic disorder or tumour.

Desoxycorticosterone↗
PubMed1985

Inadequate aldosterone response to hyperkalemia during angiotensin converting enzyme inhibition in chronic renal failure.

To assess the mechanism involved in hyperkalemia during angiotensin converting enzyme inhibition with captopril in chronic renal failure, captopril, 150 mg/day, was administered to 16 patients with hypertension with plasma creatinine levels between 1.6 and 12.4 mg/dl. After 4 weeks of therapy, plasma potassium levels increased from 3.9 +/- 0.1 to 5.5 +/- 0.2 mEq/L (P less than 0.001) and the final plasma potassium levels correlated with plasma creatinine levels (r = 0.67; P less than 0.01). In six patients with plasma creatinine levels greater than or equal to 3 mg/dl, aldosterone excretion decreased after 4 weeks of captopril, from 7.5 +/- 3.1 to 1.8 +/- 0.5 micrograms/24 hr, whereas plasma renin activity increased from 0.6 +/- 0.2 to 4.4 +/- 1.1 ng/ml/hr (P less than 0.05). This was associated with increases in plasma potassium levels from 3.9 +/- 0.2 to 5.4 +/- 0.4 mEq/L (P less than 0.005) and a significant reduction in fractional excretion of potassium from an average of 34% to 25%. No significant changes in plasma creatinine levels were observed during therapy. There was a significant positive correlation between aldosterone excretion and the potassium excretion fraction (r = 0.53; P less than 0.01). Increases in plasma potassium levels were not able to increase aldosterone excretion, although the greater the plasma potassium level attained, the smaller the reduction in aldosterone excretion (r = 0.47; P less than 0.05). Our results indicate that adequate aldosterone production is essential to preserve potassium homeostasis in chronic renal failure. Moreover, angiotensin II appears necessary for an adequate aldosterone response to potassium stimulation.

Adolescent↗
PubMed1985

The constant plasma 18-hydroxycorticosterone to aldosterone ratio: an expression of the efficacy of corticosterone methyloxidase type II activity in disorders with variable aldosterone production.

Aldosterone and 18-hydroxycorticosterone (18-OHB) are produced by the adrenocortical zona glomerulosa. Under normal conditions, plasma 18-OHB levels parallel and are influenced by the same trophic factors that regulate aldosterone production. To evaluate corticosterone-methyl-oxidase II activity, the final step of aldosterone biosynthesis, in conditions associated with chronic derangements of the pituitary-adrenal and/or renal-adrenal axis, we measured the plasma 18-OHB to aldosterone ratio, cortisol, PRA or plasma renin concentration, and potassium (K) in 104 such patients and 15 normal subjects. The 18-OHB to aldosterone ratios in the pituitary-adrenal group were not significantly different from normal regardless of elevated or reduced ACTH and/or cortisol levels [patients with Cushing's syndrome, 3.55 +/- 0.68 (+/-SE); ACTH deficiency, 2.03 +/- 0.34; 21-hydroxylase deficiency, 3.09 +/- 0.23; normal subjects, 2.50 +/- 0.15]. The renal-adrenal group also had normal ratios regardless of plasma renin concentration and K levels [patients with aldosterone-producing adenomas, 2.85 +/- 0.15; idiopathic hyperaldosteronism, 2.14 +/- 0.19; salt-losing nephropathy, 3.06 +/- 0.54; Bartter's syndrome, 2.89 +/- 0.20; isolated (hyporeninemic) hypoaldosteronism, 3.20 +/- 0.39]. Only in patients with 17 alpha-hydroxylase deficiency (230.1 +/- 118.6) was the ratio abnormally high. Chronic perturbations of aldosterone production by ACTH, the renin-angiotensin system, and/or K did not alter this last step of aldosterone biosynthesis (corticosterone-methyloxidase II), as defined by their plasma concentrations. Any influence of these trophic factors must be proximal to the site of 18-OHB production.

18-Hydroxycorticosterone↗
PubMed1985

Effects of continued adrenocorticotropin stimulation on the mineralocorticoid hormones in classical and nonclassical simple virilizing types of 21-hydroxylase deficiency.

Superphysiological doses of ACTH were administered for 3 consecutive days to nine patients with CAH, five with the classical simple virilizing (CSV) type and four with nonclassical simple virilizing type (NCSV; late onset), receiving a sodium-restricted diet. In the CSV patients, cortisol levels were lower [4.9 +/- 2.2 (+/- SEM) micrograms/dl] than in the NCSV patients (10.9 +/- 3.8; P less than 0.005) and normal subjects (10.7 +/- 4.0; P less than 0.05). ACTH produced a subnormal increase to only 14.5 micrograms/dl by day 3. In the NCSV patients, cortisol rose slowly during the first 24 h, but reached normal response levels by 48 h (42.5 +/- 11.5 micrograms/dl). In all patients, basal plasma corticosterone and 18-hydroxydeoxycorticosterone (18-OHDOC) levels were normal, but deoxycorticosterone (DOC) was elevated at 25.3 +/- 5.0 ng/dl (P less than 0.05). ACTH failed to increase plasma levels of DOC, corticosterone, and 18-OHDOC. Aldosterone and 18-hydroxycortisol were elevated in both groups [29.1 +/- 5.8 (P less than 0.02) and 83.8 +/- 15.3 (P less than 0.01) ng/dl, respectively] and increased briskly after the first 24 h of ACTH. However, neither steroid returned to normal levels in the CSV group, but both did in the NCSV group. Paired values of stimulated cortisol and aldosterone in normal subjects and CSV and NCSV patients (n = 76) were significantly negatively correlated (r = -0.63; P less than 0.001), suggesting that cortisol inhibits aldosterone biosynthesis. Prolonged ACTH administration after initial increases returned aldosterone and 18-hydroxycortisol levels from the zona glomerulosa to baseline values in the NCSV type, but not in the CSV type. The capacity to increase cortisol levels, which occurred only in NCSV patients, is linked to the reduction of aldosterone in the zona glomerulosa. In contrast, in both types of 21-hydroxylase deficiency, sustained impairment of both the 17-hydroxy pathway (cortisol) and the 17-deoxy pathway of the zona fasciculata (DOC, corticosterone, and 18-OHDOC) was demonstrated.

18-Hydroxycorticosterone↗
PubMed1984

Aldosterone-producing adrenocortical carcinoma. Preoperative recognition and course in three cases.

Three patients with primary aldosteronism due to adrenocortical carcinoma were studied, two with hyperaldosteronism alone and one also with hypercortisolism; in the later stages all three had hypersecretion of glucocorticoid and androgenic hormones. Although clinical presentations were similar to those of patients with benign adenoma, all had significantly higher concentrations of deoxycorticosterone and aldosterone and more profound hypokalemia. Stimulation with adrenocorticotropin in two patients showed a good cortisol response but no aldosterone response. The circadian rhythm for cortisol was normal but absent for aldosterone and deoxycorticosterone. Sequential 24-hour circadian studies in one patient showed that as the disease progressed, corticosterone and finally cortisol lost their circadian rhythms. Treatment with spironolactone, mitotane, or aminoglutethimide had transient clinical effects. The patients died 2 to 13 years later.

Adrenal Cortex Neoplasms↗
PubMed1984

Primary aldosteronism is comprised of primary adrenal hyperplasia and adenoma.

Primary aldosteronism due to primary adrenal hyperplasia (PAH) is described. Hypertension, hypokalaemia, hyperaldosteronism and renin suppression were corrected by unilateral adrenalectomy in 3/5 patients and by spironolactone treatment in 2/5. Blood pressure and hormonal parameters have remained normal for up to seven years after surgery and spironolactone management. Four patients had bilateral micro- and macronodular hyperplasia and one had unilateral hyperplasia. While hormonally and biochemically identical to patients with aldosterone producing adenoma, PAH can be distinguished from idiopathic hyperaldosteronism (adrenal hyperplasia). The inability to demonstrate a tumour by computed tomography but the presence of bilateral elevations of aldosterone concentration in adrenal venous blood identifies PAH.

Adenoma↗
PubMed1983

Distinctive plasma aldosterone, 18-hydroxycorticosterone, and 18-hydroxydeoxycorticosterone profile in the 21-, 17 alpha-, and 11 beta-hydroxylase deficiency types of congenital adrenal hyperplasia.

Forms of congenital adrenal hyperplasia resulting from deficient steroid hydroxylation at positions 21, 17 alpha, and 11 beta have several similar clinical and biochemical characteristics. Biochemical diagnosis has been dependent on the demonstration of elevated plasma or urinary concentrations of metabolites of the immediate biosynthetic precursor before the enzymatic block, especially after stimulation with adrenocorticotropin. Aldosterone, 18-hydroxycorticosterone, and 18-hydroxydeoxycorticosterone are not closely involved nor are they immediate precursors of any of these enzymatic defects. However, simultaneous determination of the baseline plasma levels of these steroids in patients with nonsodium-losing 21-hydroxylase deficiency (n = 12), 17 alpha-hydroxylase deficiency (n = 6), and 11 beta-hydroxylase deficiency (n = 2) revealed a consistent and distinct pattern (mean +/- SEM in nanograms per deciliter): aldosterone (28.1 +/- 2.8) and 18-hydroxycorticosterone (84.5 +/- 9.2) levels were elevated and 18-hydroxydeoxycorticosterone (8.0 +/- 0.8) levels were within normal limits in 21-hydroxylase deficiency; 18-hydroxycorticosterone (327.2 +/- 73.9) and 18-hydroxydeoxycorticosterone (236.0 +/- 33.8) levels were elevated and aldosterone (3.5 +/- 0.6) levels were reduced in 17 alpha-hydroxylase deficiency; levels of all three steroids (aldosterone 2.6 +/- 0.4, 18-hydroxycorticosterone 5.1 +/- 3.1, 18-hydroxydeoxycorticosterone 0.9 +/- 0.1) were reduced in 11 beta-hydroxylase deficiency. It is suggested that simultaneous measurement of these three steroids can be useful in identifying and further characterizing each of these forms of congenital adrenal hyperplasia.

18-Hydroxycorticosterone↗
PubMed1983

Suppression and stimulation of mineralocorticoid hormones (MCH) in the simple virilizing form of congenital adrenal hyperplasia (CAH) evaluated by the quantitation in adrenal venous blood.

Four untreated female patients with the nonsalt-losing form of congenital virilizing adrenal hyperplasia (21-hydroxylase deficiency) (21-OHD) maintained on a daily sodium intake of 120 m-equiv were studied by bilateral adrenal vein catheterization. Simultaneous right and left adrenal and peripheral blood samples were collected for determination of cortisol (F), progesterone (P), 17-hydroxyprogesterone (17-OHP), aldosterone (Aldo), and deoxycorticosterone (DOC). All patients were studied during sequential ACTH suppression (30 min after intravenous administration of 4 mg of dexamethasone) and stimulation (5 min after intravenous administration of 250 micrograms beta-ACTH [cosyntropin]). Basal peripheral concentrations of Aldo, DOC, P and 17-OHP were increased, whereas F concentrations were in the lower limit of the normal range. Dexamethasone suppressed adrenal secretion in all subjects. Subsequent adrenal stimulation by ACTH increased P, 17-OHP and DOC, whereas F returned to only control levels. DOC responses to ACTH in the adrenal vein effluents correlated significantly with Aldo responses but not with the 17-OHP increments, suggesting that the adrenal responses of Aldo and DOC to ACTH are events that probably occur in the same zone.

17-alpha-Hydroxyprogesterone↗
PubMed1983

Impaired mineralocorticoid hormone responses to adrenocorticotropin stimulation: additional characterization of heterozygosity for the 21-hydroxylase deficiency type of congenital adrenal hyperplasia.

In 12 obligate heterozygotes for the simple virilizing form of congenital adrenal hyperplasia (21-hydroxylase deficiency), basal and ACTH-stimulated levels of aldosterone, corticosterone, deoxycorticosterone, 18-hydroxycorticosterone, and 18-hydroxydeoxycorticosterone were examined. The responses to ACTH were significantly impaired (P less than 0.025 less than 0.001) compared with those of normal subjects. In addition to the often exaggerated stimulation by ACTH of the immediate precursor to 21-hydroxylation, 17 alpha-hydroxyprogesterone, the heterozygotes can now be characterized further by the impaired ACTH responses of mineralocorticoids distal to the block in the zona fasciculata; the ACTH-stimulated 17 alpha-hydroxyprogesterone/18-hydroxydeoxycorticosterone ratio was greater than normal in 94% of the heterozygotes. A limitation of 21-hydroxylation may also exist in the zona glomerulosa.

17-alpha-Hydroxyprogesterone↗