Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied in vivo and in vitro steroidogenesis in six phenotypic female children with 17-hydroxylase deficiency. The diagnosis was suspected as a likely cause of familial low renin hypertension and was confirmed by findings of reduced basal and ACTH-stimulated serum and urinary levels of cortisol and other 17-hydroxysteroids, together with hypergonadotropic hypogonadism in both 46,XY and 46,XX patients, and abnormally increased secretion of 17-desoxysteroids, such as progesterone, 11-deoxycorticosterone, and corticosterone. ACTH stimulation testing demonstrated a lesser degree of 17-hydroxylase deficiency in the obligate heterozygous parents; one father had increased basal serum 17-hydroxyprogesterone values, unresponsive to ACTH, suggesting partial Leydig cell 17,20-desmolase deficiency. In vitro kinetic analysis of testicular microsomal enzymes in the affected 46,XY male pseudohermaphrodites confirmed that both 17-hydroxylase and 17,20-desmolase activities were less than 2% of those in age-matched normal subjects. However, in spite of this virtual absence of both enzymatic activities of cytochrome P450c17, Northern blot analysis demonstrated abundant amounts of RNA in these tests that hybridized to a cDNA specific for this P450 enzyme. Moreover, immunoblot analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis-resolved testicular microsomes showed an apparently normal content of an immunoreactive protein with a mol wt similar to that of authentic P450c17. These results suggest that these patients have a point mutation in the gene for P450c17; the mutant gene is transcribed, but gives rise to a protein defective in normal 17-hydroxylase and 17,20-desmolase activities.
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PMID:Combined 17-hydroxylase and 17,20-desmolase deficiencies: evidence for synthesis of a defective cytochrome P450c17. 249 25

Studies of the mechanism of ACTH induced hypertension in sheep have led to the hypothesis that adrenocortical steroids may raise blood pressure by a "hypertensinogenic" action which can be distinguished from effects mediated by occupancy of classical mineralocorticoid or glucocorticoid receptors. This concept is supported by recent structure-activity studies using synthetic and naturally occurring steroids. Development of steroid hypertension is rapid (4-6 h) and although associated with an increase in cardiac output, changes in total peripheral resistance are important. Many different mechanisms have been proposed to explain how steroids raise blood pressure. In sheep it has been shown that the autonomic nervous system and vasoactive prostanoids appear to buffer, rather than cause, the rise in blood pressure. The renin-angiotensin system, AVP and serotonin are also unlikely to be involved. Further, the effects of steroids on blood pressure are not simply related to effects on Na status and changes in body fluid volumes. A direct involvement of the central nervous system remains to be established. In understanding how ACTH raises blood pressure, studies in sheep have shown that it is important to try and dissociate the effects of steroids involved in development of hypertension from the many other actions of steroids.
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PMID:Understanding the mechanism of adrenocortical steroid hypertension. 253 48

Inappropriate ACTH secretion with bilateral diffuse or macronodular adrenal hyperplasia is the most common cause of Cushing's syndrome. This report describes a patient with Cushing's syndrome and feminization due to ACTH-independent bilateral macronodular adrenal hyperplasia. A 47-yr-old black man presented with Cushingoid features, diabetes mellitus, hypertension, impotence, and gynecomastia. Urinary cortisol and 17-hydroxycorticosteroid excretion were 94 nmol/mmol creatinine (normal, less than 32) and 5.8 mumol/mmol creatinine (normal, 0.6-3.6), respectively. Both decreased by less than 30% after administration of dexamethasone (8 and 16 mg/day), and urinary 17-hydroxycorticosteroid excretion did not increase after metyrapone (750 mg, orally, every 4 h for six doses). Plasma ACTH was undetectable (less than 1 pmol/L) and was not stimulated by administration of metyrapone or ovine CRH. Serum testosterone was 5.2 nmol/L (normal, 7-30), FSH was 5 U/L (normal, 3-18), LH was 2.8 U/L (normal, 1.5-9.2), and estrone was 767 pmol/L (normal, 55-240). Both adrenal glands were enlarged, with a total weight of 86 g (normal, 8-10), and contained multiple nodules (diameter, greater than 0.5 cm) composed of two active cell types, one of which was also observed between the nodules. Cushing's syndrome with feminization due to ACTH-independent bilateral macronodular adrenal hyperplasia is an unusual process of unknown etiology that should be included with the other known causes of Cushing's syndrome.
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PMID:Adrenocorticotropin-independent bilateral macronodular adrenal hyperplasia: an unusual cause of Cushing's syndrome. 253 45

Abnormalities in the hypothalamo-pituitary-adrenal axis in spontaneously hypertensive rats (SHR) during development of hypertension were investigated using in vivo and in vitro methods. Plasma ACTH responses to hemorrhage and ether stress were significantly smaller in 7-week-old SHR than in age-matched Wistar-Kyoto rats (WKY), while plasma corticosterone baseline levels and its response to stress were greater in SHR than in WKY. There was no significant difference in the plasma ACTH response to ether stress between bilaterally adrenalectomized SHR and WKY replaced with a 25% corticosterone pellet for 6 days. Adrenalectomy prevented the development of hypertension in SHR; however, corticosterone replacement restored hypertension. Plasma ACTH showed a smaller response to iv CRH injection in SHR than in WKY, while the ACTH response to arginine vasopressin was not different between SHR and WKY. CRH concentrations in the median eminence, posterior pituitary, and cerebral cortex were lower in SHR than in WKY, while the CRH concentration in the median eminence was not different in SHR and WKY when they were adrenalectomized with or without corticosterone replacement. Basal in vitro CRH release from hypothalamic tissue was reduced in SHR, while CRH release in response to 56 mM KCl was not different in SHR and WKY. These results suggest that adrenocortical function is enhanced in young SHR, that reduced ACTH response to stress and exogenous CRH in SHR may be ascribed to higher plasma corticosterone levels, and that corticosterone is essential for the development of hypertension in SHR.
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PMID:Abnormalities in the hypothalamo-pituitary-adrenal axis in spontaneously hypertensive rats during development of hypertension. 254 78

The effects of prolonged (30 day) treatment with daily therapeutical doses of cyclosporine A (CSA) (20 mg/kg) on the function and morphology of adrenal cortex were studied in adult male rats. CSA-treated animals developed a notable hypertension, along with a striking rise in PRA, which was not coupled with significant changes in the plasma concentrations of aldosterone and corticosterone (hyperreninemic hypoaldosteronism). Morphometry showed that zona glomerulosa (ZG) and zona fasciculata, and their parenchymal cells were atrophic. Isolated capsular (ZG) and inner (zona fasciculata/reticularis) cells displayed reduced basal and stimulated secretory responses. However, while the response of ZG cells to angiotensin II was almost completely suppressed (96%), basal steroid secretion of isolated cells, as well as the aldosterone and corticosterone response of ZG cells to potassium and ACTH, and corticosterone production of inner cells in response to ACTH were decreased by only about 30-40%. The hypothesis is advanced that CSA exerts a dual effect on rat adrenal cortex: 1) a general inhibitory effect on the growth and steroidogenic capacity of adrenocortical cells, which manifests itself only after very prolonged treatment and may be caused by an impairment of protein synthesis; and 2) an acute effect involving the specific blockade of the angiotensin-II-induced stimulation of the secretory activity of ZG cells.
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PMID:Effects of prolonged cyclosporine-A treatment on the morphology and function of rat adrenal cortex. 254 84

We present a report on two sisters who have 17 alpha-hydroxylase deficiency with hyperaldosteronism. They have hypertension and hypergonadotropic hypogonadism. The steroid profiles suggest that they have 17 alpha-hydroxylase deficiency. In contrast to the classical biochemical findings in 17 alpha-hydroxylase deficiency, both of these patients have hyperaldosteronism. Thus this report describes a new variant of 17 alpha-hydroxylase deficiency with hyperaldosteronism. Dexamethasone suppressed the mineralocorticoid excess, including aldosterone, and improved their hypertension. In the untreated state, ACTH, instead of the renin-angiotensin system, regulated plasma aldosterone levels, but during dexamethasone treatment the renin-angiotensin system regulated these levels.
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PMID:A new variant of 17 alpha-hydroxylase deficiency with hyperaldosteronism in two Japanese sisters. 255 Feb 10

During a period of ten years, 13 children were treated for infantile spasms with ACTH. Eleven of these developed Cushing-like appearance, 9 irritability, 7 hypokalaemia, 6 metabolic alkalosis, 5 hypertension, 5 infections and 5 osteoporosis. This investigation reveals that osteoporosis is a more frequent side effect than previously recognized and, similarly, that hypertension is also a common side effect. Routine x-ray control of the thoracic spine, regular measurement of blood pressure and control of urinary calcium and serum calcium, phosphate, sodium and potassium are therefore recommended. As cases of ureteronephrolithiasis have also been observed, examination of the urine for blood and ultrasound examination of the kidneys for formation of calculi should also be considered.
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PMID:[Adverse effects in children treated with ACTH in infantile spasm]. 255 Oct 90

The clinical and endocrine characteristics of 12 Japanese patients with dexamethasone-suppressible hyperaldosteronism were compared with those in 49 Japanese patients with primary aldosteronism due to aldosteronoma. The results were as follows: 1. Most of the laboratory data in the two groups were almost the same. 2. The grade of vascular damage in both uncontrolled (3) and well-controlled (9) patients with dexamethasone-suppressible hyperaldosteronism did not correlate with blood pressure response. 3. The responsiveness of plasma aldosterone to exogenous ACTH in 6 patients with dexamethasone-suppressible hyperaldosteronism was not different from that in 9 patients with aldosteronoma. Even in 3 well-controlled patients in the former group, the plasma aldosterone response was as low as in all the 3 patients with small aldosteronomas. 4. In 4 patients with small aldosteronomas, plasma aldosterone was continuously suppressed with daily dexamethasone to the same degree as in dexamethasone-suppressible hyperaldosteronism. 5. The blood pressure, however, did not improve even in the patients with small aldosteronomas. The possible indistinguishable mechanism in dexamethasone-suppressible hyperaldosteronism and primary aldosteronism with small adenomas and the role of unknown hypertensinogenic steroid(s) other than aldosterone in inducing hypertension in dexamethasone-suppressible hyperaldosteronism are discussed.
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PMID:Study on clinical and endocrine characteristics of dexamethasone-suppressible hyperaldosteronism compared with those in primary aldosteronism owing to aldosterone-producing adenoma. 255 25

The interaction between angiotensin II (AII) and synthetic atrial natriuretic polypeptide (ANP) on the sympathetic nervous system and ACTH secretion was examined in unanesthetized, freely moving rats. Centrally administered AII (100 ng/2 microliters) caused hypertension with elevation of the plasma epinephrine level. Central administration of ANP (3 micrograms/3 microliters, 10 micrograms/3 microliters) attenuated central AII-induced pressor response and plasma epinephrine elevation. Furthermore, central AII stimulated ACTH secretion, and ANP reduced the ACTH secretion induced by AII. These results show that ANP attenuates the central AII-induced pressor response at least partially by suppressing sympathetic nervous activity, and ANP regulates ACTH secretion at the hypothalamic level.
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PMID:Atrial natriuretic polypeptide attenuates central angiotensin II-induced catecholamine and ACTH secretion. 255 15

This study investigated the anti-mineralocorticoid potency and haemodynamic effects of a series of mineralocorticoid antagonists of the spirolactone type (RU 28318, spironolactone, K-prorenoate, K-canrenoate and canrenone), for their ability to prevent the development of ACTH-induced hypertension in conscious sheep. In vivo bioassay, using aldosterone dependent changes in parotid salivary [Na+]/[K+] of sodium depleted adrenalectomized sheep, showed spironolactone was the most potent anti-mineralocorticoid tested. Infusions of the antagonists at equal doses alone for 4 days demonstrated that none affected mean arterial pressure, except for K-prorenoate which exhibited slight pressor activity. All the antagonists produced a natriuresis. Some of the steroid antagonists of the spirolactone group blocked the development of ACTH hypertension in sheep, spironolactone being the most effective. This study provides additional evidence for an essential mineralocorticoid component in ACTH-induced hypertension.
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PMID:Studies on spirolactone steroid antagonists in ACTH-induced hypertension in sheep. 255 53


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