Serum Dopamine Β-hydroxylase Research Articles

Psychotic major depression in older people: a systematic review.

This study aimed to systematically review available evidence relevant to the following issues: (1) whether psychotic major depression (PMD) in older people differs in overall severity from non-PMD, besides the presence of psychotic symptoms; (2) whether it constitutes a distinct clinical entity from non-PMD; and (3) whether it differs from PMD in younger adults. A computerized MEDLINE, PsycINFO and the entire Cochrane Library search has been performed in June 2013 for prospective controlled studies investigating PMD features in older people. Thirty-five relevant studies were identified. PMD in older people compared with non-PMD has been shown to present with overall more severe depressive symptomatology, more psychomotor disturbance, more guilt feelings, more depressive episodes with psychosis, worse prognosis, more severe executive dysfunction associated with frontal lobe atrophy, and lower serum dopamine β-hydroxylase activity. No differences in the efficacy of an antidepressant plus antipsychotic combination versus antidepressant monotherapy in the acute treatment as well as in the maintenance treatment were found. PMD in older patients is characterized by more somatic complaints and delusions of hypochondriacaland impending disaster content and by a lower comorbidity with anxiety disorders compared with PMD in younger adults. Psychotic major depression in older people is associated with higher severity in most clinically important key features than in non-PMD. However, available evidence is still insufficient for the conclusive elucidation of its nosological status. Finally, the differences between PMD in older and younger patients can be attributed to biological and psychosocial changes of old age.

Genotype-controlled analysis of serum dopamine β-hydroxylase activity in civilian post-traumatic stress disorder

Background Norepinephrine (NE) plays a central role in post-traumatic stress disorder (PTSD). Dopamine β-hydroxylase (DβH) converts dopamine (DA) to NE and its activity varies widely across individuals. Mustapic et al. (2007) reported a PTSD-associated deficit in serum DβH activity in a genotype-controlled analysis of combat veterans. We tested whether such a deficit would occur in a sample of civilians. Methods The severity of current adult PTSD symptoms and current DSM-IV diagnosis of PTSD were determined by the PTSD Symptom Scale (PSS). Adulthood trauma exposure was assessed using the Traumatic Experience Inventory (TEI). Serum DβH activity (sDβH) was assayed by HPLC with electrochemical detection and genotypes were determined using the Taqman® platform. Results Two hundred and twenty seven African American (AA) subjects were enrolled in this study, with a mean age (± SD) of 42.9 (± 12.9) years. We found a strong association between rs1611115 genotype and sDβH (p < 0.0001). After controlling for adulthood trauma exposure, there were no significant differences of sDβH between subjects who met a PTSD diagnosis and those who did not (p > 0.05) in any genotype group. No significant correlations were found between sDβH and PTSD severity, but sDβH significantly associated with the status of comorbid depression based on the cutoff of HAMD (p = 0.014) in subjects with PTSD. Conclusions We have replicated in this sample the prior finding that DBH rs1611115 genotype strongly associates with sDβH. No associations between sDβH and PTSD diagnosis or symptom severity were found in this civilian sample.

Pathogenesis of hypertension in black and white children.

Studies of cardiovascular risk factors in children conducted in the Bogalusa Heart Study provide a better understanding of the early natural history of essential hypertension. Contrasts in the biracial community of Bogalusa furnish some clues as to why essential hypertension is more prevalent in blacks. Black children tend to have higher blood pressure levels than whites. Autopsy studies and echocardiographic examinations have provided evidence of early cardiac enlargement in children and young adults with blood pressure levels in the 90th percentile. This suggests that the anatomic changes related to high blood pressure levels occur early in life. Blacks have lower plasma renin and serum dopamine beta-hydroxylase levels than whites. In general, obesity is not as closely correlated with higher blood pressure levels in black children as in white children. Prevention of hypertension should begin in early life. A major approach may be to educate children about cardiovascular risk factors and to encourage them to adopt healthy lifestyles while still young.

Peripheral markers of catecholamine metabolism among workers occupationally exposed to manganese (Mn)

In a preliminary study of 11 men randomly selected in a ferro-alloy plant and of 15 control subjects, platelet monoamine oxidase (MAO) and serum dopamine β-hydroxylase (DBH) activities were measured. A tendency towards lower MAO-B activity in the exposed workers as compared to control subjects ( t = 1.95; P = 0.06) was found whereas DBH activity was similar. In the exposed group, a dose-effect relationship was noted between a manganese (Mn) cumulative exposure index (CEI) and DBH activity ( R 2 = 0.40, P < 0.05). Since DBH is an expression of catecholamine release, the relative increase in such activity could be envisaged as a compensatory mechanism to a reduced turnover rate as reflected by MAO-B activity. Owing to the limited sample size, these findings should be confirmed by further epidemiological and experimental studies.

Serum dopamine β-hydroxylase activity in non-human primates: phylogenetic and genetic implications

1. Serum dopamine β-hydroxylase (DBH) activity is one to two orders of magnitude higher in man than in any other species previously studied. The high levels of human serum DBH are associated with the inherited allele DBH H. 2. DBH activity was measured in serum from gorillas, chimpanzees, orangutans, gibbons, rhesus monkeys and squirrel monkeys in an attempt to determine how recently in the course of evolution the allele DBH H had originated. 3. Of the non-human primates tested, only gorillas had high levels of serum DBH activity comparable to those found in man. 4. The genetic polymorphism responsible for elevated serum DBH in man is probably of very recent evolutionary origin.

25] Radioimmunoassay and immunotitration of human serum dopamine β-hydroxylase

Publisher Summary This chapter describes the radioimmunoassay and immunotitration of human serum dopamine β-hydroxylase. Dopamine β-hydroxylase (DBH) is the enzyme that catalyzes the conversion of 3,4-dihydroxy-phenylethylamine (dopamine) to the neurotransmitter norepinephrine is released with catecholamines from vesicles in the adrenal medulla and sympathetic nerves, and is found circulating in blood. The immunotitration of DBH, like other immunotitration procedures, is based on the assumption that increasing quantities of antibody will be required to bind a given fraction of antigen as the quantity of antigen is increased. In practice, several different quantities of anti-DBH antibody are incubated with aliquots of the sample being analyzed. Antibody-bound and free DBH may be separated by precipitation of the anti-DBH antibody with a second antibody. Immunotitration of human serum DBH was performed with a two-stage procedure. Incubation tubes for the first stage contained 50 μl of human serum diluted 1:6 and 50 μl of rabbit serum diluted 1:250. The observation suggests the existence of a rare variant form of DBH with decreased enzymatic activity per molecule of enzyme protein. This observation was facilitated by the ability to assay many samples simultaneously and could not have been made without the ability to measure DBH protein.

Racial differences of parameters associated with blood pressure levels in children—The Bogalusa Heart Study

Racial differences in prevalence of essential hypertension are well known. In order to explore these differences at an early age in terms of etiology, we investigated schoolchildren in an entire, biracial community. A sample of 278 children, stratified by diastolic (fourth-phase) blood pressure and specific for age, race, and sex, was reexamined 1–2 yr after initial observation for the following: (1) a physical examination and urinalysis to exclude secondary hypertension; (2) 24-hr urine sodium, potassium, plasma renin activity, and serum dopamine β-hydroxylase; (3) 1-hr oral glucose tolerance test; and (4) heart rate and blood pressure at rest and under standarized physical stress. We found that 24-hr urine sodium was positively associated with blood pressure level as measured on the same day for the high blood pressure strata of black children. Urine potassium excretion was lower in blacks than in whites, although their intakes seemed equal. In the high blood pressure strata especially, black boys had lower renin activity than whites, and the resting-supine and stressed systolic blood pressures were higher in black boys than in any other group. In these black boys, resting and stressed systolic pressures were negatively related to plasma renin activity. On the other hand, dopamine β-hydroxylase levels in white children were higher than in blacks for all blood pressure strate, and in the high blood pressure strata white children had higher 1-hr glucose levels and faster resting heart rates than black children. Different mechanisms may play a role in and contribute to the early stage of essential hypertension.

Serum dopamine β-hydroxylase (DBH) activity in acute myocardial infarction

Serial serum dopamine β-hydroxylase (DBH) activities were determined in 32 patients admitted to the Coronary Care Unit with chest pain, 9 with acute myocardial infarction and 23 with other diagnoses. The values of DBH were elevated in both groups on day one. The acute myocardial infarction group showed a slower decline and reached a baseline plateau at day five when compared to the control group whose values fell significantly by day two. The reason for the quantitative difference between the two groups is speculative and may be related to changes in plasma volume. Increases in DBH are not specific for myocardial infarction but a nonspecific response to stress.

Variations in serum dopamine beta-hydroxylase in normal subjects and chronic alcoholics.

Serum dopamine beta-hydroxylase (DBH) activity varies greatly between individuals but is usually relatively constant within individuals. DBH activity was determined in 20 normal subjects and 6 chronic alcoholics during alcohol ingestion and withdrawal, under controlled and standardized conditions. For all subjects mean random DBH was 423 +/- 249 (mean +/- SD) nmol phenylethanolamine/h per millilitre serum. Between-day serum DBH values vary more than within-day values (21.1% vs 15.1%). Cold-pressor testing or sudden standing does not increase mean DBH; however, some individuals show a significant increase which cannot be elicited on repeat testing. Mean DBH activity did not vary significantly over 24 h. Clinically useful correlations between single random DBH and blood pressure or 24-h urine catechols should not be expected.

250) - Clinical pharmacological studies on serum dopamine β-hydroxylase

250) - Clinical pharmacological studies on serum dopamine β-hydroxylase

Glycerol-induced changes in human serum dopamine β-hydroxylase activity

Glycerol-induced changes in human serum dopamine β-hydroxylase activity

Low response of serum dopamine β-hydroxylase to stimuli in primary hypertension: Decreased DβH response in hypertension

Serum dopamine β-hydroxylase (DBH), thought to reflect sympathetic nerve tonicity in man, increased 32 ± 2% (mean ± SE) in 20 normal volunteers after standing plus furosemide. There was a reduced responsiveness of 14 ± 4% ( P < 0.01) in 39 patients with primary hypertension. There were smaller increases of DBH after standing alone in subgroups of 12 normal volunteers and 11 hypertensive patients of 20 ± 5 and 9 ± 6%, respectively. Reduced DBH responsiveness was more significant in young hypertensives. The increment in DBH after standing alone was correlated directly with the changes of NE ( P < 0.05) and total CA ( P < 0.01) in the normotensives. There were no correlations of DBH changes with NE and CA changes in the hypertensives. The increment of DBH after standing plus furosemide in both normotensives and hypertensives was not proportional to changes in plasma norepinephrine (NE), total catecholamines (CA), or renin. DBH responsiveness was reduced in hypertension although the mean percentage increases of NE, total catecholamines, and renin of hypertensives after standing and standing plus furosemide were similar to those of normal volunteers. Serum DBH does not appear to be a reliable index of sympathetic nervous system activity in hypertension.

Studies on the interaction of dopamine β-hydroxylase from various sources with phytohaemagglutinins

1. 1. Bovine adrenal medulla dopamine β-hydroxylase, a glycoprotein with terminal mannose residues in the carbohydrate moiety, did not precipitate with any lectins tested except concanavalin A. After digestion with neuraminidase, the enzyme was shown to interact with ricin, and a good correlation was found between the amount of liberated sialic acids and the extent of agglutination. This finding shows either that more than one type of carbohydrate unit occurs on the protein or that three are multibranched chains in the carbohydrate moiety. 2. 2. Dopamine β-hydroxylase from human serum, pheochromocytoma and normal adrenal were incubated with concanavalin A, ricin, wheat germ agglutinin and lectins from Dilochos biflorus and Robinia pseudoacacia. 83% of dopamine β-hydroxylase from pheochromocytoma was precipitated by ricin, whereas the enzyme from human serum precipitated to a lesser extent (5–15%). Neuraminidase digestion of human serum dopamine β-hydroxylase led to an increase of precipitation with ricin. The low extent of native human serum dopamine β-hydroxylase precipitation with ricin can be explained by the attack of plasma membrane sialidases of liver cells, whereas the greater ricin precipitation of pheochromocytoma and normal adrenal dopamine β-hydroxylases could be due to post-mortem effects. The clinical implications of possibility of differences concerning the carbohydrate moiety structures of pheochromocytoma and normal enzymes is discussed.

Investigation on Huntington's disease

The possible biochemical basis underlying the aetiology and pathogenesis of Huntington's disease (H.D.) is discussed. The development of a predictive test for presymptomatic detection of the disorder, based on measurement of serum caeruloplasmin and serum dopamine beta-hydroxylase (DBH) is also described. Possible means of appraising the proposed test are suggested.

177) - Serum dopamine β-hydroxylase (DBH) activity as a maker of sympatho-adrenal activity (II)

177) - Serum dopamine β-hydroxylase (DBH) activity as a maker of sympatho-adrenal activity (II)

Serum dopamine β-hydroxylase as an index of sympathetic function

Publisher Summary This chapter describes the serum dopamine 3-hydroxylase (DBH) as an index of sympathetic function. DBH is a copper-containing mixed function oxidase that catalysis hydroxylation of the three carbon in the side chain of phenylethylamine derivatives. The enzyme has been tentatively characterized as a tetrameric glycoprotein with 1 or 2 active sites, each containing one copper molecule that undergoes cyclic oxidation and reduction. It has a molecular weight of close to 290,000. Under dissociating conditions, four subunits of molecular weight 75,000 have been reported but it is uncertain whether the units are identical or catalytically active. Enzymatic activity may depend upon the cooperative action of two or even all four subunits, and upon sugar residues that comprise 4% of the molecule. Amino acid analysis has revealed that DBH is a highly acidic protein, rich in glutamate and aspartate, and deficient in methionine and half-cystine. The enzyme requires molecular oxygen and a reducing agent as cofactors. Ascorbate is generally used to reduce the enzyme in vitro but can be replaced by dimethyltetrahydropterine. Pterines may therefore play a similar regulatory role to that proposed in the first rate-limiting step in catecholamine synthesis catalyzed by tyrosine hydroxylase.

Inhibition of human serum dopamine -hydroxylase after the oral administration of fusaric acid.

Die Dopamin-β-Hydroxylase-Aktivitat im menschlichen Serum wurde nach der oralen Zufuhr von Fusarinsaure (50–300 mg) stark gehemmt.