Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

At least two isoforms of 11 beta-hydroxysteroid dehydrogenase (11 beta-OHSD) have been identified, and clinical studies have illustrated their physiological and pathological significance. In the kidney, a high affinity 11 beta-OHSD2 inactivates cortisol to cortisone and protects mineralocorticoid receptors from cortisol. In the liver, a low affinity 11 beta-OHSD1 converts cortisone to cortisol, and may ensure that glucocorticoid receptors are adequately exposed to cortisol. In vascular smooth muscle, the conversion of cortisol to cortisone influences vascular tone. Defects in 11 beta-OHSD2 probably account for mineralocorticoid excess in the syndromes of Apparent Mineralocorticoid Excess, licorice administration, and ectopic ACTH syndrome. Defects in 11 beta-OHSD1 may be important in essential hypertension, and polycystic ovarian syndrome. The underlying mechanism for all of these defects, and the putative role of endogenous inhibitors of 11 beta-OHSD, remains unclear. In future, the measurement of the activity of individual isoforms should resolve this uncertainty.
 ...
PMID:Clinical investigation of 11 beta-hydroxysteroid dehydrogenase. 758 1

The activities of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) and 5 beta-reductase were analyzed in 39 normotensive controls and 128 patients with essential hypertension. The activity of 11 beta-HSD was obtained by dividing the 24-hour urinary tetrahydrocortisone by the sum of tetrahydrocortisol (THF) and allotetrahydrocortisol (aTHF), whereas the activity of 5 beta-reductase was obtained by dividing the 24-hour urinary THF by aTHF. The activity of 5 beta-reductase was significantly lower in essential hypertensives compared with normotensive controls (P < 0.05). However, the activity of 11 beta-HSD did not differ between normotensive controls and essential hypertensives. A positive correlation between the activities of 11 beta-HSD and 5 beta-reductase was observed in essential hypertensives (r = 0.60, P < 0.01). Neither 11 beta-HSD nor 5 beta-reductase activity correlated with indices of renal mineralocorticoid receptor activation, which were assessed by determination of plasma potassium and urinary excretion of sodium as well as potassium. Taken together, these results suggest that disturbances of one of the inactivation pathways of cortisol may contribute to the pathogenesis of hypertension.
 ...
PMID:The activities of 5 beta-reductase and 11 beta-hydroxysteroid dehydrogenase in essential hypertension. 770 42

We compared corticosteroid metabolite excretion rates and patterns in a group of 68 subjects with untreated essential hypertension and a matched group of 48 normotensive control subjects. The ratio of tetrahydrocortisol plus allotetrahydrocortisol to tetrahydrocortisone and the ratio of allotetrahydrocortisol to tetrahydrocortisol were significantly higher in the hypertensive group. This is qualitatively similar to the situation found in patients with the syndrome of apparent mineralocorticoid excess or subjects treated with licorice or carbenoxolone where hypertension is known to arise from deficiencies of 11 beta-hydroxysteroid dehydrogenase and 5 beta-reductase activities. The equivalent ratios for corticosterone metabolites were not different between groups, but total corticosterone metabolite excretion was higher in the hypertensive group. Plasma cortisol levels were lower in hypertensive than in control subjects, but corticosterone levels were higher. This evidence supports a previous suggestion that the activities of these two enzymes may be reduced in essential hypertension, but the contribution of these changes to hypertension is not known.
 ...
PMID:Evidence of coexisting changes in 11 beta-hydroxysteroid dehydrogenase and 5 beta-reductase activity in subjects with untreated essential hypertension. 784 56

Exogenous inhibitors of 11 beta-hydroxysteroid dehydrogenase (e.g. glycyrrhetinic acid, a constituent of licorice) raise blood pressure by allowing cortisol to activate mineralocorticoid receptors. Endogenous 11 beta-dehydrogenase inhibitors called glycyrrhetinic acid-like factors (GALFs), have been extracted from urine. Increased GALFs could explain the impairment of 11 beta-dehydrogenase in essential hypertension and ectopic ACTH syndrome. We extracted urine on Sep-Paks and quantified GALFs by their inhibition of 11 beta-dehydrogenase bioactivity in microsomes from rat liver. GALFs have no diurnal rhythm and were no different after dexamethasone treatment, in patients with low ACTH, on in 4 patients with ectopic ACTH secretion. In 79 subjects, GALF excretion did not correlate with blood pressure. In 17 subjects, GALF excretion did not correlate with indices of mineralocorticoid receptor activation on 11 beta-dehydrogenase activity. We conclude that GALFs are not ACTH dependent and have no measurable effect on 11 beta-dehydrogenase in vivo. In hypertension associated with impaired 11 beta-dehydrogenase activity GALFs are unlikely to play a pathophysiological role.
 ...
PMID:Endogenous inhibitors of 11 beta-hydroxysteroid dehydrogenase in hypertension. 785 15

Elucidation of a role for 11 beta-hydroxysteroid dehydrogenase (11 beta-OHSD) in modulating ligand access to renal mineralocorticoid receptors, together with identification of expression of the enzyme in most mammalian tissues, has raised the possibility (i) that glucocorticoid metabolism might influence corticosteroid receptor activation in other sites which are relevant to blood pressure control (e.g., vascular smooth muscle), and (ii) that abnormal 11 beta-OHSD expression might play a pathogenic role in common forms of hypertension (e.g., essential hypertension and the syndrome of ectopic ACTH secretion). This article reviews data from human experiments which suggest that 11 beta-OHSD has tissue-specific actions which can increase or decrease sensitivity of both mineralocorticoid and glucocorticoid receptors to cortisol, and that assessment of cortisol sensitivity may prove equally important as assessment of cortisol secretion rates in hypertensive patients.
 ...
PMID:Organ-specific actions of 11 beta-hydroxysteroid dehydrogenase in humans: implications for the pathophysiology of hypertension. 819 53

Recently, the current authors reported the presence in normotensive male and female urines of reproducibly measurable levels of naturally occurring substances in partially purified extracts of urine with inhibitory activity like glycyrrhetic acid (GA) towards both 11 beta-hydroxysteroid dehydrogenase (11 beta-OHSD) and steroid 5 beta-reductase (5 beta-SR) in vitro. Since these substances mimic two known inhibitory activities of GA, they have been named 'Glycyrrhetic Acid-Like Factors', abbreviated as 'GALFs' or, more specifically 11 beta-GALF for substance(s) active against 11 beta-OHSD, and 5 beta-GALF for those inhibitory to 5 beta-SR. Administration of glycyrrhetic acid in man leads to cortisol-dependent mineralocorticoid hypertension, owing to impaired inactivation of cortisol by 11 beta-OHSD, and may be associated with increased sensitivity to mineralocorticoids owing to impaired 5 beta-SR. In this preliminary report, the results are described of a study on the presence of GALF factors in urines collected from patients with congestive heart failure (CHF) and mild essential hypertension. The results show that in such patients there are increased amounts of both 11 beta- and 5 beta- GALFs compared to normotensive. The possible physiological significance of these results is discussed.
 ...
PMID:Inhibitors of 11 beta-hydroxysteroid dehydrogenase and 5 beta-steroid reductase in urine from patients with congestive heart failure. 829

Endocrine Hypertension, is, in a narrow sense, defined as adrenal hypertension, including mainly pheochromocytoma, Cushing's syndrome, a syndrome of primary aldosteronism and it's related mineralocorticoid excess disorders. In memory of a great contribution to hypertensiology by the late Prof. Murakami, who was the first author to write on pheochromocytoma in Japan, this paper is dedicated to reviewing the current status of adrenal hypertension in Japan from the epidemiological viewpoint, putting emphasis upon the clinical characteristics of aged patients with adrenal hypertension. Secondly, some topics in the research field of each adrenal hypertension are briefly introduced. Thirdly, our recent data are presented, showing 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) mRNA expression in resistance vessels and decreased 11 beta-HSD activities in vessels in SHR which supports the hypothesis that there might exist a subtype identified as partial impairment of 11 beta-HSD in patients with essential hypertension.
 ...
PMID:[Endocrine hypertension]. 833 19

1. The role of genetically determined changes in adrenal steroid production, metabolism and action in the pathogenesis of cardiovascular disease in man is considered by studying three loci that are important in corticosteroid function. 2. Variation at the glucocorticoid receptor locus can be identified as a biallelic restriction fragment length polymorphism (Bcl1); subjects with contrasting genotypes show altered skin vasoconstrictor responses to topically applied budesonide without any significant change in leucocyte receptor binding characteristics. 3. In a case control study of patients with essential hypertension, we have shown evidence of reduced 11 beta-hydroxysteroid dehydrogenase activity, with an elevated ratio of cortisol to cortisone metabolites in urine. 4. The genes encoding 11 beta-hydroxylase and aldosterone synthase are highly homologous. Studies in the Milan hypertensive rat show variation at this locus, which may account for the increased steroid synthesis noted in the hypertensive strain; in man, a chimaeric gene comprising 5' regulatory regions from 11 beta-hydroxylase and 3' coding sequence from aldosterone synthase accounts for the autosomal dominant condition Dexamethasone Suppressible Hyperaldosteronism. Variation in the precise location of the crossover site between the two genes does not account for the observed phenotypic heterogeneity in this condition. 5. Measurement of basal plasma steroid levels in subjects with essential hypertension show an increased ratio of 11-deoxycortisol/cortisol, consistent with reduced activity of 11 beta-hydroxylase in the zona fasciculata. 6. In summary, three loci involved in corticosteroid synthesis, metabolism and action can independently affect cardiovascular phenotypes; their roles in determining pathophysiological changes, including hypertension, remain to be studied.
 ...
PMID:Corticosteroids in essential hypertension: multiple candidate loci and phenotypic variation. 871 73

1. A patient with severe hypertension was found to have mildly impaired 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) activity on the basis of urinary steroid metabolite ratios, low plasma aldosterone, angiotensin II and renin levels and marginally low levels of plasma potassium. 2. The patient also had a compulsively high salt intake. 3. We tested the hypothesis that high salt intake may affect 11 beta-HSD activity. 4. High salt intake in normal subjects did not significantly alter either blood pressure or 11 beta-HSD activity. 5. We suggest that the potentially small hypertensive effect of the partial enzyme deficiency in our patient, also reported in patients with essential hypertension, has been markedly amplified by the very high salt intake.
 ...
PMID:Sodium status, corticosteroid metabolism and blood pressure in normal human subjects and in a patient with abnormal salt appetite. 871 74

There are striking similarities between Cushing's syndrome and the 'metabolic syndrome X' since both are characterised by hypertension, insulin resistance, glucose intolerance, hyperlipidaemia, and central obesity. The possibility that cortisol contributes to the associations between multiple risk factors for cardiovascular disease was rejected when it was demonstrated that there was no elevation in cortisol secretion or circulating concentration in patients with essential hypertension or type 2 diabetes mellitus. However, in recent years the enormous variability in tissue sensitivity to cortisol has become apparent. We have measured tissue sensitivity to glucocorticoids using an assay of skin vasoconstriction and have demonstrated its relationship with high blood pressure, insulin resistance, glucose intolerance, and hypertriglyceridaemia. Our data suggest that the increase in dermal glucocorticoid sensitivity is not a secondary phenomenon and may be explained by increased glucocorticoid receptor affinity together with impaired inactivation of cortisol by 11 beta-hydroxysteroid dehydrogenase. Importantly, we have not found that enhanced peripheral glucocorticoid sensitivity is associated with compensatory suppression of cortisol secretion, so that the maintenance of normal circulating cortisol concentrations in patients with cardiovascular risk factors may be paradoxical and inappropriate.
 ...
PMID:Abnormal glucocorticoid activity in subjects with risk factors for cardiovascular disease. 896 30


1 2 3 Next >>