Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0031511 (pheochromocytoma)
 14,622 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The clonidine suppression of urinary metanephrines as a criterion for the diagnosis of pheochromocytoma is described. Twenty-four patients were divided into 3 groups: Group I, 10 patients with pheochromocytoma (confirmed by tomography and surgery); Group II, 9 patients with suspected pheochromocytoma (clinical evidence plus one mildly elevated value of urinary metanephrines, but with negative tomography); Group III, 5 patients with proven essential hypertension. 2. Urinary metanephrine levels were determined in urine collected before (basal) and 3 h after a single oral dose of clonidine (0.4 or 0.8 mg). 3. Mean basal urinary metanephrine levels were above normal for group I (9.2 +/- 2.2 micrograms/mg creatinine) and group II (2.2 +/- 0.3 micrograms/mg creatinine) but were within the normal range for group III (0.6 +/- 0.1 microgram/mg creatinine). After clonidine administration, urinary metanephrine levels remained elevated for all patients with pheochromocytoma but decreased to within the normal range for all but one patient in group II. The urinary metanephrine levels of group III were not significantly altered by clonidine. 4. These data demonstrate that, when monitored by the clonidine suppression test, urinary metanephrine levels are useful for the diagnosis of pheochromocytoma, permitting the differentiation of affected patients from those exhibiting essential hypertension and increased sympathetic drive.
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PMID:The clonidine test for the diagnosis of pheochromocytoma: the usefulness of urinary metanephrine measurements. 369 46

Dopamine concentration, a marker of the sympathetic discharge additional to norepinephrine and epinephrine levels, was determined in 31 patients. These patients, mostly women, had essential hypertension and hypertensive episodes that mimicked pheochromocytoma, except that the patients were rather plethoric (instead of pale) and often had associated nausea, epigastric discomfort, and polyuria. During and after hypertensive paroxysms, plasma free norepinephrine and epinephrine levels did not increase, but we found a mean eightfold and 16-fold increase of free and sulfated plasma dopamine levels, respectively, and similar although less marked dopamine level increases in the urine collected following the paroxysm. The hypertensive paroxysms, spontaneous or precipitated by stimulation of the autonomic nervous system, were similar to those described by Page as simulating diencephalic stimulation. Dopamine level may be a marker of the sympathetic discharge, undetected by measurements of free norepinephrine level, and may explain some clinical features of Page's syndrome.
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PMID:Episodic dopamine discharge in paroxysmal hypertension. Page's syndrome revisited. 371 27

The concentrations of unconjugated plasma dopamine (PDA) were studied in patients with various types of hypertension. Catecholamines were extracted from plasma specimens (1.0-3.0 ml) through an Amberlite CG50 (Li+-form) microcolumn and eluted by a magnesium sulfate - ethanol solution. The elute was then desalinated and deproteinized by the ethanol-treated precipitation procedure and dried in a vacuum oven at 25 degrees C. A fraction of catecholamines was assayed with the modified procedures of the COMT-mediated radio-enzymatic method. This assay system was sensitive enough to permit an accurate measurement of PDA as low as 6.0 pg per ml of plasma without any detectable contamination of the conjugated dopamine. The resting levels of PDA were 10.1 +/- 1.0 pg/ml (mean +/- SEM), 9.5 +/- 1.0 and 13.7 +/- 0.6 in patients with borderline hypertension (BH, n = 25), essential hypertension (EH, n = 22) and renovascular hypertension (RVH, n = 8), respectively. The values in EH patients were significantly smaller than those in age-matched normal controls (13.0 +/- 1.4, n = 14, p less than 0.05). Remarkably increased PDA values were observed in patients with pheochromocytoma (76.5 +/- 25.4, n = 9, p less than 0.01). Significantly raised PDA values were also found in patients with primary aldosteronism (PA, 27.8 +/- 9.0, n = 6, p less than 0.05), while their plasma norepinephrine levels (PNE, 169 +/- 39 pg/ml) tended to be lower than those of normal controls (206 +/- 20), showing an apparent dissociation between the values of PDA and PNE. Upright posture for 15 minutes induced a significant rise in PDA (p less than 0.05) in all subjects except PA patients. The postural changes of PDA, however, were invariably smaller than those of PNE (p less than 0.05). The resting values of PDA in normal, BH and EH patients showed a significant negative correlation with their mean arterial pressures (r = -0.301, n = 61, p less than 0.05) and a positive correlation with those of PNE (r = 0.381, p less than 0.01). There was no correlation between PDA and age in any group studied. These findings indicate that PDA might not be only a precursor fraction of neurotransmitters released from the sympathetic nervous system but could also represent a physiological function of the dopaminergic regulatory system. The varied but distinctive features of PDA status in various types of hypertension suggest the possibility that the peripheral dopaminergic mechanisms play an inherent role in the pathogenesis of hypertension.
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PMID:[Plasma dopamine concentrations in various types of hypertension]. 375 30

MR-tomography was employed for examination of 41 patients with arterial hypertension (AH). Aldosteroma was diagnosed in 11 patients, pheochromocytoma in 4 patients, paraganglioma in one patient. 25 patients with essential hypertension (EH) were entered into the comparison group and 16 healthy persons into the control group. Computerized tomography of the adrenals was performed in all the examinees. In MR-tomography normal adrenals were visualized as homogeneous formations of low intensity image surrounded by high intensity image of the retroperitoneal fat. In the patients with stage I-IIA EH adrenal shape and sizes did not differ from those in the control group. Certain enlargement and deformity of the adrenals were noted in the patients with stage IIB-III EH, especially in a malignant course of disease. Aldosteroma on MR-tomograms was visualized as an additional formation in the adrenal field, had a rounded or oval shape with regular clear contours; by intensity of image the tumor was similar to the liver. In the pheochromocytoma patients the tumor was also of a rounded shape, not always with clear borders, in one case with signs of the penetration in the vena cava inferior which was clearly visualized on the frontal sections. Paraganglioma found in one patients in the hilus of the left kidney, was of an oval shape with a high intensity signal, similar to that from the sympathetic chain. A study conducted in 3 reciprocally perpendicular planes clearly showed that the tumor adjoining the aorta was unconnected with the renal vessels.
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PMID:[Diagnostic possibilities of MR-tomography of the adrenals of patients with essential hypertension]. 382 72

Plasma prolactin level and plasma renin activity were determined in normal subjects and patients with low and normal renin essential hypertension, renal hypertension, renovascular hypertension, primary aldosteronism, Cushing syndrome, pheochromocytoma and malignant hypertension. In both normal subjects and the normal renin essential hypertensives, plasma prolactin was significantly higher in females than in males. Plasma prolactin was also significantly higher in the normal renin essential hypertensives than in normal subjects of both sexes, while no significant difference was found between the low renin group and normal subjects of either sex. A significantly positive correlation was observed between plasma renin activity and the plasma prolactin level in male essential hypertensives, but not in females. Although no significant difference in plasma prolactin level could be detected between patients with secondary hypertension and normal subjects, this level was significantly higher in malignant hypertensives than in normotensives. From these results, it was shown that significant differences of plasma prolactin levels exist between normal renin essential hypertensives, and low renin essential hypertensives or normal subjects, and that these differences may partly depend on renin status which might be related to the central dopaminergic activity. In malignant hypertensives, the high level of plasma prolactin may be caused by diminished renal function, but the suppression of central dopaminergic activity cannot be excluded in the mechanism of plasma prolactin increment.
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PMID:Plasma prolactin levels in patients with essential hypertension, malignant hypertension and secondary hypertension. 388 34

The catecholamine (CA)-releasing action of metoclopramide (MCP) observed in patients with pheochromocytoma was tested in 20 subjects with essential hypertension and compared with the same effect of glucagon in 10 of them. We found that even in the absence of pheochromocytoma, MCP is a CA-releasing substance, moderately increasing systolic blood pressure and pulse rate. The release of CA is reflected by an increase in concentrations of free norepinephrine and total (free plus sulfated) epinephrine 3 minutes and of total dopamine and norepinephrine 10 minutes after the MCP bolus dose, whereas glucagon had an effect on the release of free epinephrine. Regional catheterization before and after MCP dosing in one subject showed a considerable increase in adrenal epinephrine and norepinephrine concentrations 45 seconds after the MCP bolus dose. MCP has a free CA-releasing potency much like that of glucagon. Because the released free CA is readily sulfoconjugated, the effect on CA release can be more easily detected when conjugated CA is determined. MCP should thus be used with caution in pheochromocytoma as well as in other forms of hypertension.
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PMID:Effect of metoclopramide on plasma catecholamine release in essential hypertension. 397 97

Chromogranin A is the major catecholamine storage vesicle soluble protein costored and coreleased by exocytosis with catecholamines. Immunoreactive chromogranin A circulates in human plasma, where it may reflect changes in exocytotic sympathoadrenal activity. We measured plasma chromogranin A concentration in normotensive control subjects as well as in untreated essential (primary) hypertensive subjects and subjects with several varieties of secondary hypertension. Plasma chromogranin A concentration was higher in subjects with essential hypertension (n = 32) than in normal controls (n = 18; 198 +/- 32 versus 129 +/- 12 ng/ml [mean +/- SEM]; p less than 0.05), and was also elevated in subjects with hypertension secondary to renal parenchymal disease (n = 9; 192 +/- 36 ng/ml; 0.05 less than p less than 0.1) and those with pheochromocytoma (n = 11; 1614 +/- 408 ng/ml; p less than 0.01). In essential hypertensive subjects (n = 5), short-term suppression of sympathetic outflow with oral guanabenz (4 mg) reduced plasma chromogranin A concentration within 30 to 60 minutes, while the blood pressure response was more gradual and was maximal at 3 hours. The results suggest that plasma chromogranin A is, at least in part, under neural control and that there may be an excess of exocytotic sympathoadrenal activity in essential hypertension. These initial studies are now being expanded to larger subject groups.
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PMID:Plasma chromogranin A. Initial studies in human hypertension. 399 34

A method for estimating cardiac output (CO) from the intra-arterial blood pressure profile ("contour method") was tested in 8 patients: 6 with essential hypertension, 1 with a pheochromocytoma and 1 with orthostatic hypotension. CO (1/min) was derived by the following formula: PSA (1+St/Dt) X HR 10(-3), where PSA is the area under the systolic portion of the pressure curve, St is the systolic and Dt the diastolic time, X is a correction factor, HR is the heart rate and 10(-3) is a conversion factor from ml/min to 1/min. The "contour method" was compared to the thermodilution CO method. The correlation between the 2 methods was highly significant: the r value in all patients during different conditions (supine, tilt, dynamic and static exercise) ranged from 0.91 to 0.97 with an intercept close to 0 and a slope close to 1. These results indicate that CO is properly measured from the intra-arterial blood pressure profile by the "contour method". A continuous hemodynamic monitoring can be derived applying the "contour method" to the intra-arterial blood pressure profile obtained with the Oxford technique.
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PMID:Possibility of cardiac output monitoring from the intra-arterial blood pressure profile. 400 46

Sodium permeability of erythrocyte membranes was examined, using the recording of maximum rates of sodium-lithium countertransport, in patients with essential hypertension of stages II and III by the WHO classification, renal arterial hypertension, Itsenko-Cushing disease, pheochromocytoma, Conn's syndrome and in subjects with normal arterial pressure who made up a control group. Hypertensive patients demonstrated a more than 60% increase in erythrocyte membrane permeability, as compared to normotensive controls. In patients with pheochromocytoma, the permeability values were almost 40% as low as the control ones. No changes in sodium erythrocyte membrane permeability could be demonstrated in patients with renal hypertension, Itsenko-Cushing disease and Conn's syndrome. It is believed that the erythrocyte membrane permeability parameters can be used for the identification of essential hypertension in the differential diagnosis of hypertensions.
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PMID:[Permeability of the erythrocyte membrane for sodium in hypertension and symptomatic hypertension]. 402 Dec 73

Selective venous blood sampling was performed in 89 patients with hypertension (14 pheochromocytoma, 10 Conn's syndrome, 8 Cushing's disease, 57 essential hypertension). We looked for diagnostic criteria and the valuability of blood sampling from the adrenal veins in such diseases. Defining a norepinephrine concentration of more than 8,000 ng/l as pathological, we had an accuracy of 94.6%. Defining an aldosterone concentration of more than 1,400 pg/ml as pathological, we had an accuracy of 97.4%. In Cushing's disease this method was not very helpful due to overlapping results.
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PMID:Selective blood sampling in adrenal hypertension. 405 28


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