Clinical and biochemical aspects of pheochromocytoma. Report of 110 cases

In 110 patients the diagnosis of pheochromocytoma was established by biochemical tests. These patients displayed various patterns of urinary and plasma catecholamines and their metabolites. The estimation of urinary methoxycatecholamines proved the most useful screening procedure. In patients with equivocal biochemical results the clonidine suppression test appeared to be a useful diagnostic tool. Clinical analysis displayed a bizzare course and unusual symptoms and signs in some patients. Computerized tomography and adrenal scintigraphic imaging with 131I-meta-iodobenzylguanidine were found to be the most reliable noninvasive methods for localization of the tumor.

Relationships between urinary catecholamine metabolites, particularly MHPG, and selected personality and physical fitness characteristics in normal subjects

Thirty-four normal male subjects were tested to determine the relationships between physical fitness condition (Ismail criterion), levels of self-reported depression (MMPI) and anxiety (Welsh criterion), and the urinary concentrations of 3-methoxy-4-hydroxyphenylglycol (MHPG), normetanephrine (NM), and metanephrine (M). Urinary samples were collected after sleep and during occupational activities to ascertain the effects of different psychosocial stimuli on the relationships among the variables. Univariately, urinary MHPG did not relate to physical fitness and was moderately related to depression (p less than or equal to 0.10) during the occupational period. Multivariate canonical correlational results revealed a significant (p less than or equal to 0.04) relationship between the biochemical and personality sets of variables during the occupational settings. MHPG was the most sensitive catecholamine metabolite for reflecting depressive conditions. The results suggest a biochemical reactivity syndrome involving MHPG that may relate to depressive personality characteristics.

Influence of catecholamine activity on the hierarchical relationships among physical fitness condition and selected personality characteristics

Tested male Ss (N = 34) to determine how changes in the urinary excretion patterns of selected catecholamines and their metabolites affect the multivariate relationships involving variables that measure physical fitness condition and selected personality characteristics. Urine specimens were collected from each S after sleep and during occupational activities and analyzed for six catecholamine-related variables. Those measures were combined with six personality variables (MMPI) and a physical fitness score (Ismail Criterion), and subjected to first- and second-order factor analyses. The findings indicated an association between low physical fitness and high self-reported anxious depression during the occupational period, but not at rest. The changes in the factor structures were statistically mediated by changes in the concentrations of the biochemical variables across the collection periods. This suggests that the relationships between physical fitness and personality are augmented during catecholamine reactivity to occupational stress.

DL-Threo-3,4-dihydroxyphenylserine does not exert a pressor effect in orthostatic hypotension

DL-Threo-3,4-dihydroxyphenylserine (DL-DOPS) was given to six subjects with severe orthostatic hypotension (OH). On separate days each subject took either 600 or 800 mg DL-DOPS or placebo. DL-DOPS increased norepinephrine (NE) excretion 10,000% and urinary normetanephrine and dihydroxyphenylglycol excretion 400%. DL-DOPS, however, led to only slight increases in excretion of the major NE metabolites 3-methoxy-4-hydroxyphenylglycol and vanillylmandelic acid. Only approximately 2.2% +/- 0.5% (range 0.65% to 3.8%) of the L-stereoisomer (L-DOPS), when given as DL-DOPS, is converted to NE in vivo over 24 hr. DL-DOPS did not affect either supine or upright blood pressure in our subjects. Our findings do not support reports that DL-DOPS may be therapeutically useful in OH.

A new method for the simultaneous analysis of free and sulfoconjugated normetanephrine, metanephrine, and 3-methoxytyramine in human urine by HPLC with electrochemical detection

A sensitive and specific assay for free and sulfoconjugated normetanephrine, metanephrine, and 3-methoxytyramine was achieved by tetraphenylboron complexing and by high-performance liquid chromatography with electrochemical detection. Sulfoconjugated metabolites were hydrolyzed by sulfatase. Complexing the 3-O-methylated catecholamines with tetraphenylboron followed by their extraction in either and reextraction in dilute hydrochloric acid succeeded in partially purifying the sample without the use of a prepacked column. Detection by electrochemical technique additionally eliminates unoxidable components in the urine. The relatively high sensitivity of this method permits measurement of metabolite concentrations as low as 10 ng/ml, allowing for the first time the determination of free 3-O-methylated catecholamines in human urine. Hydrolysis by sulfatase specifically identifies the form of the conjugated metabolite. The mean total (free plus sulfoconjugated) values of normetanephrine, metanephrine, and 3-methoxytyramine obtained from 25 normal volunteers were 214, 102, and 227 micrograms/day, respectively. Values were greatly increased in patients with pheochromocytoma. The degree of sulfoconjugation varied, and each individual metabolite was highest with normetanephrine (86%). This method is sensitive, rapid, simple, and can be easily standardized for clinical investigation of pheochromocytoma.

[Electrostimulation anesthesia in comparison with enflurane-nitrous-oxide inhalation anesthesia during gynecologic operations. 2. Hormonal reactions in the pre-, intra- and postoperative course]

This study describes the secretion of cortisol, growth hormone, prolactin and catecholamines before, under, and following gynaecological surgery in electrostimulation anaesthesia combined with nitrous oxide (ESA). The hormonal stress reactions of ESA were compared to inhalation anaesthesia with enflurane-nitrous oxide ( EFL ). Twenty-two patients undergoing laparotomy were allocated evenly to one of these procedures. In both groups serum levels for cortisol, growth hormone, and prolactin increased during surgery. Growth hormone showed a considerably higher increase during ESA at the end of the operation, whereas prolactin was higher at all periods of surgery during EFL . Cortisol, however, was identical for both groups. Renal excretion rates of adrenaline and noradrenaline were not significantly different. During surgery more metanephrine and normetanephrine were excreted in the urine under ESA than under EFL . There is no advantage with ESA intra- or postoperatively as compared to other routine procedures of anaesthesia for abdominal gynaecological surgery with regard to the so-called stress hormones or sympathetic activity.

Common mechanism of action of biochemically "specific" antidepressants

NE turnover in depressed patients treated with three drugs which have specifically different primary biochemical effects is compared before and after treatment. Turnover is quantitated as the sum of NE and its major metabolites excreted in the urine using a new mass spectrometric assay. Clorgyline , a MAOI specific for Type A; desipramine, a selective NE uptake inhibitor; and zimelidine, a selective 5HT uptake inhibitor, were used. All three antidepressants, including zimelidine, reduced NE turnover although producing very different effects on the metabolic profile of NE. It remains likely that effects on NE are related to therapeutic effect.

Avenues of investigation for the role of catecholamines in anxiety

Many of the cardinal somatic symptoms associated with anxiety states are produced by the sympathoadrenal medullary discharge of catecholamines (CA) described over 50 years ago as 'fight or flight' responses. During the last decade, development of sensitive convenient assays for CA and their metabolites in tissues, cerebrospinal fluid, plasma and urine has made possible assessment of brain and peripheral adrenergic activity during stress, in neuropsychiatric disorders, and after administration of drugs. Studies in animal models of stress and anxiety parallel studies in humans. In rats, there are genetic differences in the graded adrenergic alerting responses to administered or anticipated stress, analogous to trait anxiety in humans. Behavioral responses to stress may be attenuated in rats by pharmacological blockade of peripheral CA release, suggesting a positive feedback process in which released CA augment behavioral responses, possibly analogous to use of clonidine or beta-adrenergic blocking agents to diminish somatic symptoms attending anxiety-provoking situations in humans. The biochemical evaluation of adrenergic responses by examination of CA and their metabolites in body fluids of humans with various levels of sympathetic activation will be discussed.

Catecholamine metabolism during clonidine withdrawal

Abrupt cessation of clonidine treatment in hypertensive patients may precipitate a withdrawal syndrome. Since this drug is likely to be more widely prescribed to normotensive patients with neuropsychiatric diseases, we studied neurochemical, cardiovascular, and behavioral changes upon placebo substitution in seven patients receiving clonidine (6 micrograms/kg/day for 3 weeks) for treatment of alcohol amnestic disorder. Urinary excretion of all major catecholamine metabolites returned to pretreatment levels 3-5 days after discontinuing clonidine, without significant overshoot. The percentage increase during clonidine withdrawal of the norepinephrine metabolite normetanephrine was greater than were those of vanillylmandelic acid, 3-methoxy-4-hydroxyphenylglycol (MHPG), or the epinephrine metabolite metanephrine. Excretion of the dopamine metabolites homovanillic acid and 3-methoxytyramine did not change. Total plasma MHPG, heart rate, and mean arterial pressure were significantly elevated above pretreatment values 72 h after the last dose of clonidine. There was an enhancement of episodic memory compared to predrug values but no other behavioral changes were noted during clonidine withdrawal. These findings are consistent with augmented catecholamine release and central noradrenergic activation which may produce psychopathology in some psychiatric patients during clonidine withdrawal.

Urinary catecholamine metabolites distinguish different types of sympathetic neuronal dysfunction in patients with orthostatic hypotension

Urinary excretion rates of the major norepinephrine metabolites, 3-methoxy-4-hydroxymandelic acid, 3-methoxy-4-hydroxy-phenylglycol and normetanephrine, were determined in 12 normal subjects and 23 patients with neurogenic orthostatic hypotension due to either multiple system atrophy [Shy-Drager Dyndrome (MSA)] or idiopathic orthostatic hypotension (IOH). There were striking and parallel decreases in all catecholamine metabolites in IOH consistent with loss of peripheral sympathetic nerves. Patients with MSA excreted greater amounts of the deaminated metabolites than did the patients with IOH, but most excreted equally low amounts of normetanephrine. The disproportionate decrease in excretion of normetanephrine by patients with MSA is consistent with observations in experimental animals that O-methylation is the primary metabolic route for active released norepinephrine, whereas deamination is the predominant metabolic route for intraneuronal degradation of the catecholamine. The similar proportional decreases in all catecholamine metabolites in patients with IOH (who have no central nervous system deficit) indicates that brain norepinephrine is a source of only a small fraction of urinary norepinephrine metabolites, including 3-methoxy-4-hydroxy-phenylglycol.

Excretion of catecholamine metabolites during methadone maintenance and withdrawal

Catecholamine metabolites excreted by long-term methadone hydrochloride-dependent subjects were studied in a protocol involving a two-study design. After a two-week methadone maintenance period, 15 subjects underwent abrupt methadone withdrawal and 12 subjects, gradual methadone withdrawal. The first study compared levels of catecholamine metabolites excreted during the stable methadone period with those excreted during the abrupt withdrawal period, as well as with those eliminated by healthy nonaddicted controls. No changes in the excretion of 3-methoxy-4-hydroxyphenylglycol and normetanephrine were noted between the methadone maintenance period and the time of abrupt methadone withdrawal. These values did not differ from those obtained for controls. However, higher levels of metanephreine were excreted during the stable methadone period than those in controls. During withdrawal, levels of metanephrine dropped a statistically significant amount in comparison with levels observed during the stable methadone period. The gradual withdrawal study confirmed these findings.

Reliability of urinary monoamine and metabolite output measurements in depressed patients

The authors measured urinary monoamines and their metabolite outputs in 12 unmedicated depressed patients. Output of 3-methoxy-4-hydroxy-phenylglycol and vanillylmandelic acid proved to be relatively stable from one sample to another. An average of at least two measures provided data with a meaningful reliability for normetanephrine, serotonin, and homovanillic acid output. Output of dopamine, norepinephrine, 5-hydroxyindoleacetic acid, and phenylethylamine was highly variable over time.

Electroconvulsive treatment and lithium carbonate. Their effects on norepinephrine metabolism in patients with primary, major depressions

Effects of electroconvulsive treatment (ECT) and lithium carbonate on norepinephrine metabolism were investigated in eight patients with primary, major depressions. A series of 12 ECTs reduced urinary norepinephrine and normetanephrine output significantly, and showed a tendency to reduce urinary vanillylmandelic acid output as well as whole-body norepinephrine turnover. Treatment with lithium carbonate significantly reduced urinary norepinephrine, normetanephrine, 3-methoxy-4-hydroxyphenylglycol, and vanillylmandelic acid output as well as whole-body norepinephrine turnover. These findings point to a common effect of antidepressant treatments since they are similar to results produced by administration of three other types of antidepressant drugs: clorgiline, a specific monoamine oxidase A inhibitor; desipramine, a relatively specific norepinephrine reuptake Inhibitor; and zimelidine, a relatively specific serotonin reuptake Inhibitor. These drugs reduce total production of norepinephrine and/or its major metabolites in depressed patients. Thus, five antidepressant treatments with different mechanisms of action have a common overall effect on the system.

High-performance liquid chromatography with electrochemical detection for the simultaneous determination of the methoxylated amines, normetanephrine, metanephrine and 3-methoxytyramine, in urine

A simple method for the simultaneous analysis of normetanephrine, metanephrine and 3-methoxytyramine (both free and conjugated) in human urine by reversed-phase ion-pair high-performance liquid chromatography with electrochemical detection has been developed. Existing methods have been optimized for extraction by study of analytical parameters. The hydrolysed urines are purified and concentrated by successive passages on two ion-exchange resins and ammoniacal elution to eliminate interference from pigments or related chemical compounds. The methoxyamines are separated by high-performance liquid chromatography on a reversed-phase column. Detection and quantitation are achieved with an electrochemical detector using a vitreous carbon electrode. Samples can be injected at 25-min intervals. Reference values of adults and children are given.

Assessment of norepinephrine secretion and production

A noninvasive method is described for assessing the disposition of NE produced by peripheral sympathetic neurons. Total NE production is estimated from integrated NE metabolite excretion. The rate at which NE enters the bloodstream (apparent NE secretion) is estimated by isotope dilution analysis. The rate at which NE is metabolized locally is calculated by subtracting apparent NE secretion from NE production. In 10 normal volunteers, basal NE production by the peripheral sympathetic nervous system was 11.1 +/- 1.0 nmol/m2/min. Apparent NE secretion, by contrast, was only 2.4 +/- 0.18 nmol/m2/min. Our data thus demonstrate that in normal individuals under basal conditions, at least 78% of the NE produced by the sympathetic nervous system undergoes local metabolism and that no more than 22% of NE diffuses into the circulation.

Endogenously synthesized prostaglandins stimulate sympathetic nervous system activity

We examined the effect of an increase of endogenous prostaglandin production, induced by potassium depletion, on the urinary excretion of the norepinephrine metabolites metanephrine, normetanephrine and MHPG. Potassium deficiency caused a significant increase in all three metabolites. Treatment with indomethacin, 10 mg/day for 5 days, partially reversed the increase in the urinary excretion of norepinephrine metabolites. These findings suggest that in the intact organism prostaglandins stimulate, rather than inhibit norepinephrine release. Stimulation of prostaglandin synthesis may lead to an increase in sympathetic nervous system activity by a direct action or via a baroreceptor feedback mechanism.

Determination of urinary normetanephrine and metanephrine by radial-compression liquid chromatography and electrochemical detection

A procedure has been developed for determining the O-methylated catecholamine metabolites, normetanephrine and metanephrine, in urine by use of radial-compression liquid chromatography followed by electrochemical detection. Normetanephrine and metanephrine are isolated from hydrolyzed urine by ion-exchange on small, commercially available, disposable columns and preconcentrated by solvent extraction. They are then separated by reversed-phase ion-pair chromatography, with use of a radial compression cartridge and radial compression module, and quantified with 3-methoxy-4-hydroxybenzylamine as internal standard. Normetanephrine, metanephrine, and the internal standard are separated from interfering peaks in about 15 min. The method is applicable to the relatively low amounts of normetanephrine (100-600 micrograms/24 h) and metanephrine (50-400 micrograms/24 h) found in normal subjects and patients with depressive disorders or hypertension. Within-day CVs ranged from 1.1 to 2.2% for normetanephrine and 1.2 to 6.9% for metanephrine; the corresponding between-day CVs were 4.9 and 5.7% over these ranges.

Biological and psychological aspects of a case of Gilles de la Tourette's syndrome

The case of a 12-year-old girl with Gilles de la Tourette's syndrome is presented, and the following factors are discussed: psychological aspects, urinary excretion of 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) and unconjugated amines, and CT scan findings. The most noticeable differences from normal controls seen in the urine studies were elevated levels of beta-phenylethylamine and the catecholamine metabolites normetanephrine, MHPG, and 3-methoxytyramine, and a decrease in 5-hydroxytryptamine. A CT scan revealed a slight increase in density in the caudate nuclei bilaterally; this was thought to be due to calcification.

Monoamine metabolites as predictors of antidepressant response: a critique

Monoamine metabolite measurements are being increasingly used for making nosological, symptomatological and pharmacological profiles of the affective disorders. A number of unresolved methodological issues question the validity of using baseline metabolite levels for predicting treatment response. Some studies show correlations between baseline metabolite levels and response to treatment with specific antidepressant agents. Effects of antidepressant treatment on metabolite levels may be useful in predicting drug response.

Urinary excretion of O-methylated catecholamines, tyramine and phenyl-ethylamine by volunteers treated with tranylcypromine and CGP 11305 A

To assess the effect of the new, selective, reversible MAO A inhibitor, CGP 11305 A (4-(5-methoxy-7-bromo-benzofuranyl-2-)piperidine HCl), on MAO A and B activity in man, the daily excretion of total normetanephrine (NMN), metanephrine (MN), 3-methoxytyramine (3-MT) and beta-phenylethylamine (PEA) was measured in the urine of healthy volunteers treated with weekly increasing doses from 40 to 150 mg/d. A similar study was carried out with tranylcypromine in weekly increasing doses from 10 to 25 mg/d. Both compounds increased the excretion of NMN; with CGP 11305 A, a plateau was obtained at 50 mg/d, and tranylcypromine 20 mg was more effective than 10 mg, and was also more active than the highest dose of CGP 11305 A. Increases in MN and 3-MT produced by the latter compound were comparable to that in NMN, whereas tranylcypromine had a biphasic effect on MN excretion, and caused only a small increase in 3-MT excretion. CGP 11305 A up to 150 mg/d did not alter total tyramine excretion, whereas tranylcypromine at 20 mg caused a definite increase. Tranylcypromine led to 4-6 fold increases in PEA output at 20 and 25 mg/d, but not at 10 mg. No such effect could be demonstrated for CGP 11305 A up to 150 mg/d. These results suggest that in man MAO A was inhibited by CGP 11305 A in daily dose of 40 mg or more, whereas it did not affect MAO B at up to 150 mg.(ABSTRACT TRUNCATED AT 250 WORDS)

Alteration of norepinephrine metabolism with desipramine and zimelidine in depressed patients

Twelve patients with a major affective disorder were treated during the depressed phase of their illness with desipramine hydrochloride and/or zimelidine hydrochloride, and urinary excretion rates of norepinephrine and its major metabolites were examined. During treatment with desipramine, daily urinary excretion of norepinephrine, 3-methoxy-4-hydroxyphenylglycol (MHPG), and vanillylmandelic acid was reduced, but urinary normetanephrine excretion was not significantly changed. In all patients, the proportion of urinary norepinephrine metabolites represented by normetanephrine was increased during desipramine treatment. Independent of treatment outcome, desipramine seemed to decrease total formation and metabolism of norepinephrine, which was reflected in decreases in the excretion rate of the catecholamine and its metabolites. These results are consistent with known actions of desipramine on the disposition of norepinephrine and represent alterations in the rate of norepinephrine formation and metabolism, resulting from inhibition of norepinephrine reuptake. Zimelidine, a new antidepressant, which is a relatively specific serotonin-uptake inhibitor, significantly reduced only urinary MHPG excretion without appearing to alter "whole-body" norepinephrine turnover. This effect of zimelidine on norepinephrine metabolism was unexpected. Current and previous findings concerning clorgyline, a relatively specific monoamine oxidase A inhibitor, suggest that three pharmacologically distinct classes of antidepressants, norepinephrine and serotonin-reuptake and monoamine oxidase type A inhibitors, all reduce central norepinephrine turnover in depressed patients.

High correlation of norepinephrine and its major metabolite excretion rates

Twenty-four-hour urinary excretion rates of norepinephrine, normetanephrine, 3-methoxy-4-hydroxyphenylglycol, and (vanillylmandelic) acid were repeatedly measured in 12 depressed patients. High (greater than. 83) positive correlations were found between the excretion rates of these four substances. Based on these findings, the conclusion was reached that in depressed patients the 24-hour urinary excretion rates of norepinephrine and any of its three major metabolites reflect total norepinephrine production in the body.

A simple method for the assay of urinary metanephrines using high performance liquid chromatography with fluorescence detection

A method is described which extends a high performance liquid chromatographic assay for urinary catecholamines to the assay of urinary metanephrines. The amines are separated from urine after acid hydrolysis of conjugates by ion-exchange chromatography, and then further purified by solvent extraction. The final extracts are suitable for direct HPLC assay using the endogenous fluorescence of the amines for detection. Twenty-four hour excretion of the amines in 35 hospital in-patients was found to be (mean and range: 169 micrograms/24 h normetanephrine (39-423), 102 micrograms/24 h metanephrine (19-290) and 138 micrograms/24 h 3-methoxytyramine (32-234)).

Pharmacokinetic studies of oral L-threo-3,4-dihydroxyphenylserine in normal subjects and patients with familial amyloid polyneuropathy

The pharmacokinetics of oral L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) was studied in 7 normal subjects and 7 patients with familial amyloid polyneuropathy. Each person swallowed a single 300 mg dose in the fasting state, and L-threo-DOPS in plasma and urine was determined by high performance liquid chromatography with an electrochemical detector after separation on a boric acid gel column. L-threo-DOPS was slowly absorbed by normal subjects; the maximum plasma concentration occurred 3 h after administration and 20% of the oral dose was recovered unchanged in the urine within 12 h. It induced a substantial elevation of plasma norepinephrine levels, the peak being attained at 5 h, but without any change in blood pressure. In the patients, the absorption and metabolism of L-threo-DOPS were delayed, and a prolonged pressor response was observed, with a peak after 8 h. It was concluded that the effects on plasma norepinephrine and blood pressure of oral L-threo-DOPS were essentially equal to those of twice as large a dose of DL-threo-DOPS.