Ultrasensitive stain for proteins in polyacrylamide gels shows regional variation in cerebrospinal fluid proteins.

A new silver stain for electrophoretically separated polypeptides can be rapidly and easily used and can detect as little as 0.01 nanogram of protein per square millimeter. When employed with two-dimensional electrophoresis, it should permit qualitative and quantitative characterization of protein distributions in body fluids and tissues. It has been used to demonstrate regional variations in cerebrospinal fluid proteins.

Essential hypertension: central and peripheral norepinephrine.

The concentration of norepinephrine in cerebrospinal fluid from patients with essential hypertension is higher than that from healthy normal volunteers, but the concentrations of norepinephrine in plasma from these groups are similar. This finding indicates that central nervous system noradrenergic hyperactivity occurs in essential hypertension but apparently is not reflected in abnormal function of the peripheral sympathetic nervous system in these patients.

Huntington's dementia. Clinical and neuropsychological features.

The neuropsychiatric syndrome of Huntington's disease is outlined in this report with an emphasis on the cognitive deficits that lend themselves to future neurobehavioral research. Eighteen patients without disabling cognitive or psychiatric symptoms were evaluated for a period of 3 to 15 weeks, with assessment of their cognitive disorder, psychiatric, and neurological symptoms. Neuropsychological examination included repeated mental status examination, the Wechsler Adult Intelligence Scale (WAIS), and, for some, parietal lobe testing. In addition to suffering from a loss of finely detailed memories, patients demonstrated impaired organizing, sequencing, planning, and recalling of information on request. On the WAIS, mean verbal and performance scores were not significantly different. Neuropsychological findings suggested that the Huntington's disease pattern of cognitive impairment is not initially diffuse and homogeneous, but characterized by a relative sparing of several higher cortical functions. Many patients had increased irritability and labile affect. The similarity of Huntington's disease to frontal lobe syndromes is also discussed.

Abnormalities in CNS monoamine metabolism in anorexia nervosa.

Patients with anorexia nervosa have disturbances of mood, appetite, and neuroendocrine function. Central nervous system monoamine pathways modulate these systems, and alterations in function of these systems may occur in anorexia nervosa. Because monoamine metabolism can be influenced by nutritional intake, we studied anorectics before and at intervals after correction of weight loss. Underweight anorectics had a 30% decrease in CSF homovanillic acid level and a 20% decrease in CSF 5-hydroxyindoleacetic acid concentration; these values returned to normal shortly after weight recovery. The CSF level of norepinephrine (NE) in underweight anorectics and in these patients a few weeks after weight restoration was similar to that in normal subjects. Long-term weight-recovered (20 +/- 7 months) anorectics, however, had a 50% decrease in CSF NE level compared with that of controls. Underweight anorectics have state-associated disturbances in dopamine and serotonin metabolism. Changes in NE metabolism are more complex and state independent. These abnormalities in neurotransmitter metabolism are part of the neurobiological syndrome of anorexia nervosa and may contribute to the characteristic changes in mood, behavior, and neuroendocrine function.

Altered serotonin activity in anorexia nervosa after long-term weight restoration. Does elevated cerebrospinal fluid 5-hydroxyindoleacetic acid level correlate with rigid and obsessive behavior?

To avoid the confounding influences of malnutrition or weight loss, we studied patients with anorexia nervosa at normal weight and stable dietary intake. Compared with 15 controls, 17 long-term weight-restored anorectic subjects had elevated concentrations of cerebrospinal fluid 5-hydroxyindoleacetic acid, the major serotonin metabolite, whereas levels of cerebrospinal fluid homovanillic acid, the major dopamine metabolite, were normal. Elevated levels of cerebrospinal fluid 5-hydroxyindoleacetic acid may indicate increased serotonin activity. Such activity could contribute to pathological feeding behavior. Most importantly, this study raises the question as to whether increased cerebrospinal fluid 5-hydroxyindoleacetic acid levels are associated with overly inhibited, anxious, or obsessive traits.

Probenecid-induced norepinephrine elevations in plasma and CSF.

Probenecid administered in divided oral doses totaling 100 mg/kg increased levels of norepinephrine (NE) in plasma and cerebrospinal fluid (CSF). This technique is commonly used to measure the rate of accumulation of acidic metabolites of certain brain neurotransmitter biogenic amines in CSF after blockade of their transport into blood. Since levels of 3-methoxy-4-hydroxy-phenylethyleneglycol, a neutral metabolite of NE, are also elevated after high oral doses of probenecid, the increases of CSF and plasma NE levels may be directly related to probenecid-induced release of this amine from noradrenergic neurons. In patients who experienced nausea or vomiting there were lower levels of probenecid in CSF, probably secondary to diminished absorption of the medication. These patients also had lower levels of NE in plasma than did patients who remained asymptomatic.

Conversion of MHPG to vanillylmandelic acid. Implications for the importance of urinary MHPG.

Deuterium-labelled 4-hydroxy-3-methoxyphenylglycol (MHPG), when administered intravenously, is rapidly converted to 4-hydroxy-3-methoxymandelic acid (or vanillylmandelic acid [VMA]) or conjugates of MHPG. Since over half of either racemic D,L-MHPG or the natural D-MHPG is converted to VMA and since about half of urinary VMA is derived from MHPG, estimates of the proportion of urinary MHPG derived from the brain must be revised. The results indicate that only about one fifth of urinary MHPG is derived from the brain, and clearly urinary MHPG cannot be used as a valid index of brain norepinephrine metabolism. While these observations do not alter the value of urinary MHPG as a predictor of therapeutic response or in subclassifying affective disorders, it is clear that new research questions must be formulated and appropriate investigations completed before the relationship of urinary MHPG to affective disorders is understood.

Central and peripheral ACTH and cortisol levels in anorexia nervosa and bulimia.

To explore the relationship of central and peripheral adrenocorticotropic hormone (ACTH, or corticotropin) levels to hypothalamo-pituitary-adrenal axis dysfunction in patients with eating disorders, levels of cerebrospinal fluid (CSF) and plasma ACTH, cortisol, and 24-hour urinary free cortisol were measured in 16 patients with anorexia nervosa (60% +/- 1.1% of ideal body weight), 14 patients with bulimia (93.2% +/- 4.6% of ideal body weight), and 11 healthy age-matched women volunteers. The CSF, plasma, and urinary free cortisol levels were elevated in underweight anorexic patients and showed declines following weight recovery. Cortisol-binding globulin levels were similar in anorexics and controls. In contrast, underweight anorexics showed low CSF ACTH levels that returned to normal following weight recovery, and their plasma ACTH levels were normal. On hospital admission, bulimic patients demonstrated normal ACTH and cortisol levels. After their abstinence from binge-purge episodes, the CSF ACTH levels decreased significantly. Positive relationships were found among CSF, plasma, and urinary cortisol levels, and inverse relationships were seen between cortisol measures and CSF ACTH levels in patients with eating disorders. Secretion of ACTH into the CSF may respond to feedback by cortisol or, alternatively, may be suppressed by the hypersecretion of corticotropin-releasing hormone, leading to the depletion of the pro-opiomelanocortin molecule.

Studies on the transfer of steroid hormones across the blood-cerebrospinal fluid barrier in the Rhesus Monkey.

Indwelling canulae were placed in the lateral ventricles of the brains of six adult male rhesus monkeys, and the movement of estradiol-17beta (E2), testosterone (T), and 5alpha-dihydrotestosterone (DHT) across the blood-cerebrospinal fluid (CSF) barrier was measured. Serial samples of blood and CSF were collected every 30 minutes during a 6 hour infusion of the tritiated steroids, and the quantity of free steroid in the blood and CSF was determined by recrystallization to constant specific activity. During the course of the 6-hour infusion, the average CSF concentration of steroid, expressed as dpm/ml, was about 3.5% of the concurrent plasma level of E2, 1.6% of the concurrent plasma level of T, and 0.08% of the concurrent plasma level of DHT. It is proposed that these differences in steroid transfer can be attributed to differential binding of these steroids to testosterone-estrogen-binding globulin (TeBG) in plasma.

Studies on the transfer of steroid hormones across the blood-cerebrospinal fluid barrier in the rhesus monkey. II.

The movement of progesterone (P), cortisol (F) and 17-hydroxyprogesterone (17-OHP) across the blood-cerebrospinal fluid (CSF) barrier was determined using six adult male rhesus monkeys with indwelling canulae in the lateral ventricles of their brains. Tritiated steroids were given iv as a bolus followed by a constant 6 h infusion with continuous collection of CSF and periodic sampling of blood before and during the infusion. The amounts of authentic steroid in the plasma and CSF were determined by recrystallization to constant isotopic ratio and the amount of free plasma steroid was determined by equilibrium dialysis against Ringer's solution. Tritiated progesterone was undetectable in the pooled samples of CSF. The average concentration of tritiated 17-OHP in the CSF was 10.3% of the concurrent plasma level while the concentration of tritiated F was 22.5% of the concurrent plasma level. Plasma free steroid was found to be 2.2% for P, 6.3% for 17-OHP and 22.3% for F, showing a rough correlation between steroid entry into the CSF and free steroid concentration in plasma.

The adrenal medullary response to hypoglycemia in patients with orthostatic hypotension.

The epinephrine response to insulin-induced hypoglycemia has been studied in patients with orthostatic hypotension and in control subjects. Normal subjects had a brisk increase in plasma epinephrine and norepinephrine levels which occurred at the nadir of plasma glucose levels. After the nadir of hypoglycemia, glucose recovery was biphasic, with an initial rapid rise in glucose, followed by a more gradual return to normoglycemia. In a group of 16 patients with orthostatic hypotension, 12 had deficient plasma catecholamine responses to hypoglycemia, and of these, 7 had almost no plasma epinephrine response. Comparison of the plasma epinephrine responses and the course of plasma glucose elevations indicated that a mean plasma epinephrine level of over 200 pg/ml is necessary for the rapid initial phase of glucose recovery. There does not appear to be any relationship between the etiological basis of the autonomic dysfunction and deficient epinephrine response.

Catecholamine metabolism in primary anorexia nervosa.

Abnormalities in neuroendocrine function and sympathetic nervous system activity appear to be present in primary anorexia nervosa. Hypothalamic catecholamines are involved in control of endocrine function and norepinephrine is released from sympathetic nerve endings. Because of possible abnormalities in catecholamine metabolism, plasma levels of norepinephrine and urinary excretion of homovanillic acid and 3-methoxy-4-hydroxyphenyl glycol were studied in female patients with primary anorexia nervosa before and after significant clinical improvement and compared with normal female volunteers. During the phase of the disease in which body weights were more than 20--25% below ideal, patients' blood pressures and pulse rates, plasma levels of norepinephrine, and 24-h urinary excretion of 3-methoxy-4-hydroxyphenol glycol and homovanillic acid were lower than those of a group of normal volunteers. After weight gain, these parameters increased to near-normal levels. At no time was plasma dopamine-beta-hydroxylase activity abnormal. The results suggest that abnormalities in catecholamine metabolism in primary anorexia nervosa are caused by starvation, and that neuronal functions dependent on aminergic neurotransmission may be altered as a result.

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.

Elevated cerebrospinal fluid levels of immunoreactive corticotropin-releasing hormone in anorexia nervosa: relation to state of nutrition, adrenal function, and intensity of depression.

To study the pathophysiology of hypercortisolism in anorexia nervosa, we measured the cerebrospinal fluid (CSF) levels of corticotropin-releasing hormone (CRH) in patients when they were underweight and at intervals after weight restoration. CSF CRH levels were significantly elevated in hypercortisolemic underweight patients. Both CSF CRH levels and pituitary-adrenal function normalized after weight recovery. A significant positive correlation was found between CSF CRH levels and depression ratings in weight-corrected patients. We conclude that the hypercortisolism of anorexia nervosa reflects a defect at or above the hypothalamus which results in the hypersecretion of endogenous CRH. The positive correlation between CSF CRH and depression in the weight-restored patients is compatible with previous data indicating increased CRH secretion in the depressed phase of primary affective disorder and supports the notion of a relationship between CRH and depressive symptomatology. Moreover, these data are compatible with observations that depression is part of the anorexia nervosa syndrome.

Cerebrospinal fluid probenecid studies: a reinterpretation.

Probenecid is used to block the transport of acid monoamine metabolites from cerebrospinal fluid (CSF), on the assumption that the resultant rise in CSF concentrations of the metabolites will reflect presynaptic "turnover" of the parent monoamine. However, CSF levels of probenecid correlate with CSF levels of the metabolite, suggesting that the blockade is incomplete at the probenecid levels obtained in human studies. This article reviews the literature on CSF probenecid-metabolite correlations and presents data demonstrating variations in the correlations across diagnostic groups. These cross-diagnostic variations may be due to group differences in membrane transport characteristics and and confound attempts to "correct for" CSF probenecid concentrations in studies of monoamine turnover.

Biogenic amine activity in response to fluoxetine and desipramine in differentially reared rhesus monkeys.

BACKGROUND: It has been hypothesized that adverse early experience may be a mechanism by which children become vulnerable to later psychopathology via alteration of neurochemical or hormonal systems associated with such disorders. Such effects may in turn affect later responses to pharmacologic agents that act on these systems. METHODS: In this study, 18 mother-reared (MR) and 18 peer-reared (PR) rhesus monkeys experienced six 1-week separations from cagemates interspersed with 1-week reunions, while housed in like-reared groups of 3. Within rearing groups, equal numbers of animals received either fluoxetine (2 mg/kg), desipramine (5 mg/kg) or placebo delivered daily beginning 4 weeks before the first separation. Levels of norepinephrine (NE), the NE metabolite MHPG, the dopamine metabolites DOPAC and HVA, and the serotonin metabolite 5HIAA were measured in CSF samples collected approximately every 2 to 3 weeks during these procedures. RESULTS: Following treatment, DMI increased NE and decreased MHPG in the DMI-treated groups, while 5HIAA was decreased in the fluoxetine-treated groups following treatment. The increase in NE was followed by a sharp decline over the course of treatment, which was accompanied by an increase in MHPG. The rearing groups did not show a differential response to the drug treatments, and the separation manipulation itself had few effects. The mother-reared group showed higher levels of NE and DOPAC over all samples and higher levels of HVA in most samples. CONCLUSIONS: These rearing effects on biogenic amine activity were observed even in the presence of pharmacologic treatments that effectively altered the activity of these systems, and are consistent with previous findings from the same subject. The higher NE values observed in mother-reared infants over separations and reunions may have been due to higher basal levels of NE than peer-reared monkeys or to greater responsiveness to the stress of repeated social disruption or both. These findings agree with other primate studies showing that rearing differences persist beyond the infancy period and add to growing evidence of the important influence of the early social environment on neurobiologic development in primates.

Disturbances of noradrenergic systems in normal weight bulimia: relationship to diet and menses.

Several lines of evidence suggest that noradrenergic (NE) disturbances occur in normal-weight bulimic patients. The purpose of this study was to investigate factors that may be related to noradrenergic disturbances. First, we measured plasma NE during bingeing and vomiting. We found that this behavior activated the sympathetic nervous system. Bingeing produced a significant increase in the duration and the peak increase of plasma NE when compared with normal controls eating a large meal. Second, we assessed basal peripheral and central NE levels near in time (within several days of hospital admission) to chronic bingeing and vomiting. At this time, bulimics had normal basal plasma and CSF NE levels. Finally, we restudied the same patients after 30 days of inpatient hospitalization and observed abstinence from bingeing and vomiting. In this last state, bulimics had a reduction of basal plasma and cerebrospinal fluid (CSF) NE levels compared with themselves on admission and compared with healthy controls. This study confirms that reduced noradrenergic activity occurs in normal-weight bulimic women and suggests that this abnormality may emerge during abstinence from bingeing. We hypothesize that dietary intake is related to noradrenergic activity, but cause and effect remain uncertain. Noradrenergic disturbances did not appear to be related to weight, depression, physical activity, or amino acid precursors. Lower CSF NE levels were found in amenorrheic bulimic women in both states, suggesting that a noradrenergic disturbance may be associated with the frequent incidence of amenorrhea in bulimic women.

Rearing experience and biogenic amine activity in infant rhesus monkeys.

In this report we present evidence that early social experience influences aspects of the function of brain biogenic amine systems, most notably the noradrenergic system. Biogenic amine activity was studied in mother- vs. peer-reared monkey infants over the first 6 months of life and in response to two housing transitions. Norepinephrine (NE), 3-methoxy-4-hydroxyphenylglycol (MHPG), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) levels in cerebrospinal fluid (CSF) were measured. Peer-reared monkeys showed significantly higher CSF levels of norepinephrine and MHPG than mother-reared animals over early development, but showed an attentuated NE response to separation and group formation compared to mother-reared animals. Peer-reared monkeys showed a greater developmental decline in 5-HIAA levels than mother-reared monkeys. There were no rearing effects for DOPAC or HVA over early development; however, peer-reared monkeys showed significantly lower HVA and DOPAC concentrations at 6-8 months of age. The results add to evidence for the influence of primate mothers on the psychobiological development of central nervous system neurotransmitter systems in their infants, and suggest that the noradrenergic system is among the more sensitive of these to early experience.

Urinary catecholamine metabolites and effects of clonidine in patients with alcohol amnestic disorder.

Seven normotensive patients with alcohol amnestic disorder were treated with 2 micrograms/kg clonidine (C) three times daily for 1 wk. Four patients received 12 micrograms/kg/day during the subsequent week; three developed hypotensive symptoms at this dose and remained on 6 micrograms/kg/day. During a predrug placebo period and after 60 hr on each dose of C, urinary excretion rates of catecholamine metabolites were determined. C, 6 micrograms/kg/day, reduced the ratio of norepinephrine (NE) metabolites (mumol/24 hr) to normetanephrine (NM), vanillylmandelic acid (VMA), and 3-methoxy-4-hydroxyphenyl glycol (MHPG). The excretion of metanephrine (M) was not reduced significantly. The ratio M/NM and M/(VMA + MHPG) increased, indicating Cs effects are primarily noradrenergic. Reduction in NM/(VMA + MHPG) indicates disproportionate lowering of the O-methylated metabolite of NE compared to its deaminated metabolites, consistent with C inhibition of NE release. Patients with the highest predrug NM excretion had the greatest decrements with C. The dopamine metabolites 3-methoxytyramine and homovanillic acid were not decreased by C. C-induced reductions in the ratio NM/(VMA + MHPG), an index of NE release, correlated (n = 7) with reductions in supine systolic blood pressure, mean arterial pressure, and salivary flow rate.

Effects of clonidine on central and peripheral catecholamine metabolism.

Cerebrospinal fluid (CSF; n = 5) and plasma (n = 7) levels of norepinephrine (NE) and its major metabolite, 3-methoxy-4-hydroxyphenylglycol (MHPG) were examined in abstinent normotensive men with alcohol amnestic disorder during placebo and after 2 wk of clonidine treatment (6 or 12 micrograms/kg/day). Clonidine reduced concentrations of NE and both free and total MHPG in CSF and plasma. The CNS contribution to CSF free MHPG also decreased (as estimated from the differential reductions in CSF and plasma levels). Percent reductions in CSF and plasma NE were substantially greater than those for MHPG, suggesting diminished CNS and peripheral NE release and turnover. CSF levels of homovanillic acid (HVA), which is derived solely from CNS dopamine metabolism, rose in each patient, whereas the CSF serotonin metabolite, 5-hydroxyindoleacetic acid, did not change. Thus the increase in HVA cannot be attributed to inhibition of acid transport from brain to blood. Changes in central noradrenergic and dopaminergic activity correlated inversely; thus diminished NE release and enhanced dopamine metabolism may both contribute to the effects of clonidine in man.