Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0085580 (essential hypertension)
14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The time courses of change in renin activity after cold storage of human plasma at -5 degrees C and pH 7.4 were examined in 5 normal subjects, 6 patients with essential hypertension and one female patient with primary aldosteronism before and after extirpation of the adrenal tumor. In the 5 normal subjects and 6 essential hypertensives, the gradual increase in plasma renin activity was observed until 10 days of cold storage. The same result was obtained in the case of primary aldosteronism. However, there was no increase in renin activity despite of cold storage for 10 days in plasma which was sampled from this patient 45 days after operation. These data indicate that a period of 4 days for cryoactivation of human plasma renin as has been reported by Sealey et al. is not sufficient to accomplish activation of renin by cold storage.
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PMID:Change in plasma renin activity by cold storage of plasma in normal subjects and patients with essential hypertension and primary aldosteronism. 45 2

Aberrations in the metabolic pathways of catecholamines in patients with neural crest tumors result in characteristic urinary excretion patterns of their catabolites. Tumors such as pheochromocytoma, neuroblastoma and ganglioneuroma usually defy clinical diagnosis because of their rarity, small size, intraabdominal position and clinical symptoms similar to those of essential hypertension. Quantitative determination of catecholamine metabolites such as vanillylmandelic acid (VMA) and 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) offers possibilities for reliable confirmation of diagnosis. However, previous techniques for the assessment of catabolite levels suffered from inadequate sensitivity, reproducibility or specificity, which seriously diminished their usefulness as biochemical determinants in the prognosis of these life-threatening tumors. Reported in this paper is the analysis of urinary levels of VMA and MHPG using reversed-phase high-performance liquid chromatography with electrochemical and sectrophotometric detection. We present the excretion patterns showing these metabolites in 15 control subjects, 15 patients with pheochromocytoma and 5 patients with neuroblastoma.
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PMID:Diagnosis of neural crest tumors by reversed-phase high-performance liquid chromatographic determination of urinary catecholamine metabolites. 54 40

The renal prostaglandins PGS2 and PGE2 possess potent antihypertensive and vasodepressor activity. The mechanism of blood pressure lowering effect is through peripheral arteriolar dilation with a fall in total peripheral resistance. PGA unlike PGE escape degradation by the lung and thus could circulate as antihypertensive hormones. Since plasma PGA levels rise in humans on a low sodium intake, it has been postulated that the beneficial effects of a low sodium diet in some hypertensives may be the result of an increase in peripheral vasodilating PGA. Support that plasma PGA may be a regulator of systemic blood pressure is also derived from the fact a PGA-secreting renal tumor was associated with a fall in blood pressure and a rise in plasma PGA in a previously hypertensive woman. The removal of the tumor resulted in a return of blood pressure to elevated levels and a concomitant fall in PGA. Recently, a number of human patients with essential hypertension have been infused with PGA1 and PGA2. It was observed that there was an initial increase in renal blood flow, sodium and water excretion which was associated with no change in the elevated blood pressure. When blood pressure ultimately fell, there was a return of renal blood flow, sodium and water excretion to preinfusion levels. It would appear that PGA compounds act as 'ideal' antihypertensive agents since they favorably effect renal resistance, sodium and water homeostasis, plasma volume, total peripheral resistance, blood pressure and indirectly cardiac output through baroreceptor stimulation, all factors known to be important in etiology in human hypertension.
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PMID:Renal prostaglandins. 110 Oct 92

We used 131I-19-iodocholesterol as an adrenal-imaging agent in 27 hypertensive patients who had biochemical evidence of abnormalities in the renin-angiotensin-aldosterone system. In 10 of 12 patients in whom the biochemical findings suggested the presence of an aldosterone-producing adenoma the adrenal uptake was asymmetric. The adenoma was subsequently confirmed in all eight patients in this group who underwent operation. In contrast, the adrenal uptake was asymmetric in only one of 13 patients with biochemical evidence of iodopathic hyperaldosteronism or low-renin essential hypertension. Two patients with adrenal carcinoma causing primary aldosteronism did not concentrate the isotope in their tumors. When metabolic studies suggest an aldosterone-producing adenoma, adrenal imaging with 131I-19-iodocholesterol may locate the tumor before operation.
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PMID:Location of aldosterone-producing adenomas with 131I-19-iodocholesterol. 124 8

Urinary methoxyamine determination is considered as the most sensitive and specific parameter for the diagnosis of pheochromocytoma. Since blood sampling is easier to perform, we developed a new HPLC method to assay metanephrine (MN) and normetanephrine (NMN) in plasma. We now report the results for total (free and conjugated) MN and NMN in 22 cases of pheochromocytoma compared to 26 healthy subjects, 33 patients with essential hypertension, 14 with miscellaneous diseases and 4 patients with renal failure. The mean normal values (mean +/- SD) were 0.40 +/- 0.10 ng/ml for MN and 0.85 +/- 0.25 ng/ml for NMN. The sum of MN+NMN was 1.25 +/- 0.28 and the range 0.9-1.9. In essential hypertension, the range of NMN+MN was 1.2-6.0. In the 4 renal failures, both MN and NMN were drastically increased. In 49 samples drawn from 22 pheochromocytomas, MN was elevated over the hypertensive range in 34 samples and NMN in 47 samples. The total MN+NMN ranged from 6.2 to 436 ng/ml; this figure was observed whatever the clinical presentation even in silent tumors or in paroxysmal forms between the crisis. After tumor removal, the values dropped rapidly. In conclusion, plasma determination of MN and NMN provides a highly sensitive and specific biological pointer for the diagnosis of pheochromocytoma in patients without renal failure.
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PMID:Measurement of plasma methoxyamines for the diagnosis of pheochromocytoma. 168 51

Blood antioxidant system parameters were examined in elderly subjects. The authors have developed methods for measurements of catalase, superoxide dismutase, and lipid peroxidation products. They introduce a new factor 'F' that is supposed to characterize the blood antioxidant system; this factor is based on the values of catalase and superoxide dismutase activities and the intensity of lipid peroxidation. The authors come to a conclusion that the blood antioxidant and oxidant systems may be more accurately described with the use of this new factor F. In case of an abdominal tumor whole blood catalase level is elevated and superoxide dismutase activity significantly reduced. Factor F values were found extremely low before death, therefore this factor may be considered an important criterion of a critical state. The blood antioxidant parameters of patients with diabetes mellitus and essential hypertension did not much differ from those of age-matched healthy subjects.
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PMID:[Determination of the antioxidant properties of the blood and their diagnostic significance in the elderly]. 172 48

The presence of endothelin (ET) in tumor tissue and plasma of patients with pheochromocytoma was studied by radioimmunoassay. Immunoreactive (ir-) ET concentrations in 12 pheochromocytomas ranged from 66 to 253 fmol per gram wet tissue (gwt) (146 +/- 20 fmol/gwt, mean +/- SEM). These values were not significantly higher than tissue ir-ET concentrations of two primary aldosteronism (66 and 132 fmol/gwt) and three normal adrenal glands (71-120 fmol/gwt) (0.05 less than p less than 0.1). However, tumor tissue ir-ET concentrations in six of the 12 pheochromocytomas were higher than 132 fmol/gwt (the upper value of the control tissues). Sephadex G-50 column chromatography and reverse-phase high-performance liquid chromatography of pheochromocytoma tumor extracts showed a major peak eluting at an identical position to synthetic ET-1. Plasma ir-ET concentrations of pheochromocytomas (1.4 +/- 0.9 fmol/ml, n = 17) were not significantly different from those of patients with essential hypertension (1.0 +/- 0.7 fmol/ml, n = 20) and normal subjects (1.0 +/- 0.4 fmol/ml, n = 18) (0.05 less than p less than 0.1). This study has shown that high concentrations of ET-1 are present in tumor tissues of 50% of pheochromocytomas.
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PMID:Immunoreactive endothelin in pheochromocytomas. 172 1

89 patients were operated on for pheochromocytoma. 61 patients (37 women and 24 men) were available for extended follow-up. The final survey, performed 79.1 +/- 66.9 months postoperatively, provided data on survival, blood pressure tumor recurrence, malignant metastatic lesions, cardiovascular complications and coexisting diseases. There were 4 deaths during the follow-up period, including 2 instances of malignant pheochromocytoma. Permanent normalization of blood pressure was achieved in 38 patients (62.3%). This hypotensive effect was noted in 79.2% of patients with preoperative paroxysmal hypertension and in 40.8% of those with sustained hypertension. Permanent or re-developing postoperative hypertension was noted in 23 (37.7%) patients. This includes 4 cases of malignant pheochromocytoma, 4 cases of recurrent benign pheochromocytoma and 15 cases of essential hypertension. Cardiovascular complications during follow-up were rare and concerned the patients with essential hypertension diagnosed postoperatively.
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PMID:Long term follow-up after surgical removal of pheochromocytoma--observations in 61 patients. 176 Aug 86

Excess production of aldosterone secondary to an adrenal tumor or bilateral hyperplasia is a known, but infrequent, cause of hypertension. A more frequent adrenal abnormality, observed in 30-40% of hypertensive patients, is a functional derangement in aldosterone secretion. Two such conditions have been described: low renin essential hypertension and non-modulating essential hypertension. Both have in common 1) an abnormality in the interaction of angiotensin II (Ang II) with the adrenal and 2) sodium sensitivity of the blood pressure. However, the pathophysiological mechanisms for the sodium sensitivity and hypertension are different. In normal subjects, the response of the adrenal glomerulosa cell to Ang II varies with the level of sodium intake, with sodium restriction enhancing the response. In one group of hypertensive patients with low plasma renin levels, the normally reduced aldosterone responses to Ang II on the high salt diet do not occur. Thus, these individuals have an enhanced adrenal response to Ang II under circumstances in which it should be reduced, thereby leading to lower renin levels and a tendency toward sodium retention. The second group has the opposite defect; that is, on a low sodium diet, they have a reduced adrenal response to Ang II. This results in a normal or high plasma renin level. The sodium sensitivity of their blood pressure arises not from the adrenal abnormality but from the associated defect in sodium-dependent, Ang II-mediated changes in renal blood flow. Thus, on a high salt diet, these patients, who are termed "non-modulators," fail to increase renal blood flow, thereby leading to a sodium-retaining state.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Functional derangements in the regulation of aldosterone secretion in hypertension. 193 78

Chromogranin A, co-stored and co-released with catecholamines from adrenal medullary and sympathetic neuronal vesicles, is elevated in the plasma of patients with pheochromocytoma. The usefulness of the hormone in the differential diagnosis of hypertension is examined. An elevated level of chromogranin A had comparable diagnostic sensitivity (83%, 24/29) to, but greater diagnostic specificity (96%, 86/90) than the level of plasma catecholamines when subjects with pheochromocytoma (n = 29) were evaluated in comparison to several reference groups, including normotensive controls (n = 49), subjects with essential hypertension (n = 28), subjects with renovascular hypertension (n = 5), and subjects with primary aldosteronism (n = 3). Subjects with signs or symptoms suggesting pheochromocytoma, but in whom the diagnosis was ultimately ruled out (n = 5) had normal plasma levels of chromogranin A. A modest rise in chromogranin A in those with essential hypertension, and correlation of chromogranin A with diastolic blood pressure in normotensive patients and patients with essential hypertension did not impair the diagnostic usefulness of chromogranin A for pheochromocytoma. Renal failure was associated with an elevated plasma chromogranin A independently of blood pressure. Plasma chromogranin A correlated with tumor mass, tumor chromogranin A content, tumor norepinephrine content, and urinary vanillylmandelic acid excretion; it did not correlate with plasma or urinary catecholamines, nor with blood pressure in patients with pheochromocytoma. Plasma chromogranin A levels did not differ in subjects with pheochromocytoma when stratified by age, sex, tumor location, or tumor pathology. Several drugs used in the diagnosis or treatment of pheochromocytoma (clonidine, metoprolol, phentolamine, and tyramine) had little effect on plasma chromogranin A concentration. Within the pheochromocytoma, chromogranin A was localized along with catecholamines to the soluble core of chromaffin granules, where it accounted for 18 +/- 5% of vesicle soluble protein. We conclude that 1) chromogranin A emerges along with catecholamines from pheochromocytoma chromaffin granules; 2) plasma chromogranin A is a sensitive and specific diagnostic tool in evaluation of actual or suspected pheochromocytoma; 3) plasma chromogranin A predicts pheochromocytoma tumor size and overall catecholamine production; and 4) drugs commonly employed in the diagnosis or treatment of pheochromocytoma have little effect on plasma chromogranin A level, preserving the usefulness of chromogranin A in evaluating pheochromocytoma. Thus, measurement of chromogranin A provides a useful adjunct to the diagnosis of pheochromocytoma.
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PMID:Chromogranin A storage and secretion: sensitivity and specificity for the diagnosis of pheochromocytoma. 198 65


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