Plasma Dopamine Research Articles

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Simultaneous Determination of Salsolinol Enantiomers and Dopamine in Human Plasma and Cerebrospinal Fluid by Chemical Derivatization Coupled to Chiral Liquid Chromatography/Electrospray Ionization-Tandem Mass Spectrometry

A sensitive, specific, and robust method to simultaneously determine enantiomeric salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, SAL), a potential biomarker implicated in alcohol-related neurotoxicity in a stereoselective manner, and its precursor dopamine (DA) has been developed using simple chemical derivatization and chiral separation coupled with electrospray ionization-tandem mass spectrometry (ESI-MS/MS). SAL enantiomers and DA were converted to stable pentafluorobenzyl (PFB) derivatives directly from aqueous media. Bulky PFB groups introduced into the SAL structure enabled baseline separation of SAL stereoisomers on a chiral column without cumbersome chiral derivatization to unstable SAL diastereomers. Subsequent analysis by ESI-MS/MS with multiple reaction monitoring (MRM) in the presence of deuterium-labeled internal standards allowed specific detection of both derivatives with a wide dynamic range (SAL, 0.5-5000 pg; DA, 0.02-20 ng). The limit of quantitation assayed in the plasma matrix was below 10 pg for each SAL enantiomer and 100 pg for DA. Both coefficient of variance and error for inter- and intraday measurements in the blank plasma were less than 10% for SAL and DA in the concentration range of 10-4000 pg/mL and 0.1-8 ng/mL, respectively. This strategy enabled routine and specific determination of both SAL enantiomers and DA from 0.5 mL of human plasma and cerebrospinal fluid, which has not been possible using existing methodologies.

Elevated Plasma Dopamine Metabolites in Cannabis Psychosis

Back to table of contents Previous article Next article Letters to the EditorFull AccessElevated Plasma Dopamine Metabolites in Cannabis PsychosisMALCOLM B. BOWERS M.D.JOSHUA T. KANTROWITZ M.D.,MALCOLM B. BOWERS M.D.Search for more papers by this authorJOSHUA T. KANTROWITZ M.D.Search for more papers by this author,Published Online:1 Oct 2007https://doi.org/10.1176/appi.ajp.2007.07010217AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail To The Editor: Cannabis has received increasing attention as a risk factor for the development of psychotic states (1) . There are relatively little data related to the biochemical profile in cannabis psychosis (2 , 3) . We report on five consecutive cases of first-admission psychosis associated with documented cannabis use. For comparison, we used a consecutive series of first-admission psychosis and a group of nonpsychotic inpatients treated during the same period. We collected plasma for homovanillic acid on the first morning after admission following an overnight fast. The first-admission cannabis psychosis group (N=5) had a mean age of 21.2 years. Urine tests were positive for cannabis subjects on admission. The comparison groups had urine samples negative for cannabinoids on admission. The first-episode psychosis group (N=15) had a mean age of 20.4 years, and the nonpsychotic group (N=17) had a mean age of 32.0 years. The psychosis groups did not significantly differ in age, race, sex, or level of psychosis. The degree of psychosis was rated as moderate on the four positive symptom items of the Brief Psychiatric Rating Scale.Plasma homovanillic acid was measured using gas chromatography mass spectrometry with deuterated internal standards. Homovanillic acid levels were compared using a Student’s t test. Plasma homovanillic acid values were as follows: cannabis psychosis group, 24.8 ng/ml (SD=2.9); first-episode group, 15.1 ng/ml (SD=3.1); and nonpsychotic group, 9.6 ng/ml (SD=2.1). Homovanillic acid values for the cannabis group were significantly higher relative to the first-episode group (p<0.001) and the nonpsychotic group (p<0.001). Homovanillic acid values for the first-episode group were significantly higher when compared with the nonpsychotic group (p<0.001). To our knowledge, this is the first report of elevated plasma homovanillic acid in cannabis-related psychosis, although we are aware of a report of elevated urinary homovanillic acid following cannabis administration to a volunteer population (2) . In this small case series of patients with first-episode psychosis associated with cannabis use, plasma homovanillic acid was significantly higher than values for each of the comparison groups. There are several possibilities for this result. First, plasma homovanillic acid is elevated in a number of newly admitted psychosis patients (4) , which was the case in our first-episode psychosis group. However, plasma homovanillic acid was even higher in the cannabis group. Second, acute cannabis administration can produce increased dopamine activity in animals and humans (2 , 3) . Third, individuals with cannabis psychosis may also have a genetic vulnerability that can lead to increased dopaminergic activity (1) . New Haven, Conn.The authors report no competing interests.This letter (doi: 10.1176/appi.ajp.2007.07010217) was accepted for publication in July 2007.Reprints are not available; however, Letters to the Editor can be downloaded at http://ajp.psychiatryonline.org.

Dopamine beta‐hydroxylase (DBH) activity and ‐1021C/T polymorphism of DBH gene in combat‐related post‐traumatic stress disorder

The roles of dopamine (DA) and norepinephrine (NE) in posttraumatic stress disorder (PTSD) are unclear. The aim of the study was to determine plasma dopamine beta-hydroxylase (DBH) activity and DBH-1021C/T gene polymorphism in combat veterans with (N = 133) or without (N = 34) chronic PTSD. Similar frequencies in genotype or allele distribution were found between veterans with or without PTSD. War veterans with PTSD had lower DBH activity, associated with the DBH-1021C/T variant in DBH genes, than veterans without PTSD. A significantly lower plasma DBH activity was found in combat veterans with PTSD carrying the CC genotype as compared to veterans without PTSD carrying the corresponding genotype. Since both groups were exposed to the same trauma, it is possible that a pre-existing trait difference in regulation of NE function contributed to a differential vulnerability to develop PTSD, or that the regulation of DBH expression was different in response to trauma. The results suggest that that genotype-controlled measurement of plasma DBH activity might be used as a potential biological marker of the response to trauma, and that further studies of DBH and other loci related to DA and NA in PTSD are warranted.

Plasma dopamine in workers exposed to urban stressor

The aim of this study is to evaluate if the occupational exposure to urban stressor could cause alterations in dopamine (DA) plasma levels and related diseases in traffic police officers compared to a control group. After excluding subjects with principal confounding factors, 306 traffic police officers (139 female and 167 male) and 301 controls (134 female and 167 male) were included in the study. In traffic police officers, mean DA values were significantly higher compared with controls (P = 0.006 and P = 0.000 in male and female, respectively). The distribution of DA values in traffic police officers and controls was significant (P = 0.000 and P = 0.000 in male and female, respectively). The number of male traffic police officers with a positive response to the questionnaire's items concerning anxiety, depression and panic attacks was higher than controls, though not significant (7.2% traffic police officers versus 4.2% controls). This difference was also not significant in female traffic police officers compared with controls. According to our previous researches on other neuro-immune-endocrine parameters, DA could be used as an early biological marker, valuable for the group to be employed in occupational sets, even before the onset of pathology.

ANG II-induced attenuation of salt gland function in Pekin ducks is not catecholamine-dependent

Pekin ducks (Anas platyrhynchos) were bilaterally adrenalectomized (biADX), injected with 1 mg of triamcinolone (TRIAM) kg bw(-1) im and given 0.9% saline drinking water during a 24 h recovery period followed by chemical sympathectomy with 6OH DOPA 3 h before the start of experimental observations. Baseline plasma dopamine (DA) concentrations decreased from 283 +/- 88.5 pmol ml(-1) to 42.4 +/- 11.1 pmol ml(-1); epinephrine (E) from 142 +/- 46 pmol ml(-1) to 18.4 +/- 9.2 pmol ml(-1) and norepinephrine (NE) from 742 +/- 84 pmol ml(-1) to 406 +/- 38 pmol ml(-1) 1 day after biADX + TRIAM but before chemical sympathectomy. Baseline MABP increased from 132 +/- 3.2 mmHg to 209 +/- 14.3 mmHg (P < 0.05) in response to TRIAM. After chemical sympathectomy with 6OH DOPA there was an additional 90% decrease in plasma NE to 42 +/- 9.4 pmol ml(-1) and a concurrent 60% decrease in MABP to 83.4 +/- 6.9 mmHg (P < 0.05). Nasal fluid secretion was maintained by the continuous infusion of hypertonic saline (1,000 mosmol kg H(2)O(-1) at a rate of 0.3 ml kg(-1) min(-1)). Rates of nasal fluid secretion and fluid electrolyte concentrations were unchanged following biADX + TRIAM + 6OH DOPA. Angiotensin II (ANG II; dose 1 microg kg bw(-1) i.v.), attenuated nasal fluid secretion showing that the response to ANG II was not NE- dependent. Plasma NE concentrations decreased following Tyramine i.v. (33 +/- 8.5 pmol ml(-1)) there being no vasopressor response. This is the first report of the ANG II induced attenuation of duck salt gland secretion in the absence of measurable E and NE.

Genotypic and haplotypic associations of the DBH gene with plasma dopamine β-hydroxylase activity in African Americans

Several variants at DBH are significantly associated with plasma DbetaH activity (pDbetaH). However, the overwhelming majority of data on this genotype-phenotype relationship has been gathered in samples from Europeans and European Americans (EAs). In this study, we examined the relationship between DBH polymorphisms and pDbetaH in samples from African-American (AA) subjects. Genotypes were determined at a 19-bp insertion/deletion polymorphism (ins/del) and four single-nucleotide polymorphisms (SNPs) at DBH in 109 samples. Analyses were performed using analyses of variance (ANOVAs) (for individual SNPs) and regression procedures (to assess the joint effects and the specific SNP-based haplotypes). We found: (1) single-variant analysis of all polymorphisms revealed apparent associations to pDbetaH, with rs1611115 accounting for the largest proportion of the variance in pDbetaH (28.7%) and ins/del the smallest (6.5%); (2) modest but significant linkage disequilibrium (LD) existed between ins/del and rs1611115; (3) LD between all other pairs of variants was not observed; (3) stepwise regression showed that a model containing rs1611115, rs2519152 and rs6271 accounted for 37.6% of the variance in pDbetaH, with rs6271 showing additional 7.6% above the effect of rs1611115, and rs2519152 showing additional 2% above rs1611115 and rs6271; (4) two common haplotypes, C-T-C and T-C-C at rs1611115-rs2519152-rs6271 were significantly associated with pDbetaH (P=0.0025 and 0.0036, respectively). The data support the validity of prior reported associations and underscore the importance of analyzing multiple SNPs across DBH in future association studies examining disease and biochemical phenotypes.

Dopamine levels after repetitive transcranial magnetic stimulation of motor cortex in patients with Parkinson's disease: Preliminary results

Repeated session of repetitive transcranial magnetic stimulation (rTMS) over motor cortex have been reported to produce significant improvement of motor performance in patients with parkinson's disease (PD). In addition, it is known that a single session of rTMS over motor cortex transiently increases DA in striatum. Here, we test whether repeated sessions of rTMS increase serum dopamine in PD patients and whether this correlates with changes in clinical rating scales. Twenty untreated PD patients with moderate to severe symptoms (Hoehn & Yahr state III-V 1967) were assessed on the Unified Parkinson's Disease Rating Scale (UPDRS), and with an enzyme immunoassay for quantitative determination of plasma dopamine before and after six daily sessions of 25 Hz rTMS with 3,000 stimuli over the right and left hand and leg motor cortex. There was significant improvement in UPDRS compared with the baseline. Serum dopamine level also was significantly elevated over the same interval. There was a significant correlation between UPDRS and serum dopamine level before and after treatment. Improved motor performance in PD after repeated session of rTMS may be related to an elevation of serum dopamine concentration.

Plasma dopamine and noradrenaline variations in response to stress

Dopamine (DA) the precursor of noradrenaline (NA) has been shown to have many functions such as its influence on endorphins activity and its association with hedonic impact, anxiety and depression. However with regard to the sympathetic nervous system activity, the role of DA has merely been considered as being the precursor of NA. We have shown in a previous study a positive correlation between the resting plasma level of NA and those found during exposure to a physical stress. No explanation was proposed to explain this finding. Enhanced sympathetic nervous system activity has been shown to increase the secretion of NA as well as DA. It is not known however if the secretion of DA during exposure to stress parallels that of NA. What are the interactions between the two amines and also between values at rest and during exposure to stress? For that reason a test was used which consisted of blowing cold wind (4 °C at 60 km/h) on the face of a group of subjects and measuring plasma concentration of the two amines before, during and after the test. For a given individual, the increase of either plasma NA or DA in response to the cold wind stress parallels the resting plasma concentrations of these two amines respectively. Low level of one amine at rest coincides with low increase during the stress. Furthermore the results have shown that when the plasma level of either one of these two amines is high in response to stress, the values of the other amine are small; both amines are not high or low at the same time. The literature suggests that dopamine beta hydroxylase (DBH), the enzyme which catalyzes the synthesis of NA from DA, may provide an explanation to our findings. Lower DBH activity of this enzyme would result in a lower NA and a greater DA storage and secretion. Further investigation is needed to verify this possibility.

Effect of Gosha-Jinki-Gan, a Blended Herbal Medicine, on Bladder Activity in Rats

We investigated the effect of the blended herbal medicine Gosha-jinki-gan on bladder activity and the autonomic nervous system in rats. A total of 42 female rats were divided into a control diet group of 21 and a Gosha-jinki-gan diet group of 21. Rats in the control diet group were fed a standard diet, while animals in the Gosha-jinki-gan were fed a special diet containing 1.08% Gosha-jinki-gan (TJ107, Tsumura Co., Tokyo, Japan). After 4 weeks 28 rats, including 14 in the control and 14 in the Gosha-jinki-gan group, underwent continuous cystometry with physiological saline or 0.1% acetic acid solution and bladder activity was recorded. The remaining 14 rats were anesthetized with halothane, and body weight, serum amino acid (glutamate and glycine) and plasma monoamine (noradrenaline, adrenaline, dopamine and serotonin) levels were measured. The amplitude of bladder contraction on continuous cystometry with physiological saline was lower in the Gosha-jinki-gan diet group than in the control diet group, and plasma dopamine and serotonin levels were also lower in the Gosha-jinki-gan group. When cystometry was done with 0.1% acetic acid, the interval between bladder contractions was shortened in the control and Gosha-jinki-gan groups. However, the interval and duration of bladder contractions were longer in the Gosha-jinki-gan than in the control group. These results suggest that Gosha-jinki-gan inhibits bladder activity by maintaining the balance of the sympathetic and parasympathetic nervous systems at a low level.

Inhibition of lipopolysaccharide stimulated interleukin-1β production after subarachnoid hemorrhage

Purpose: To identify the characteristics of cytokine production from peripheral blood mononuclear cells (PBMCs) in response to lipopolysaccharide (LPS) in patients with subarachnoid hemorrhage (SAH).Methods: Blood samples were collected on the first day and 3 days after SAH (n=12) to measure plasma concentrations of catecholamines, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β and IL-10. PBMCs from SAH patients or healthy volunteers were incubated with LPS (1 μg) for 24 hours. In the second phase, PBMCs from healthy volunteers (n=6) were incubated with or without catecholamine (10 μmol/l) for 6 hours. After pre-treatment, the cells were treated with LPS (1 μg) for 18 hours. Supernatants were extracted and subjected to measurement by enzyme-linked immunosorbent assay.Results: Plasma concentrations of epinephrine or dopamine prolong increased significantly 3 days after SAH, involved in elevation of plasma IL-10. In the PBMCs from the SAH patients, LPS-stimulated IL-1β production was inhibited significantly. Pre-treatment with epinephrine or dopamine inhibited LPS-stimulated IL-1β production significantly in the PBMCs from the healthy volunteers.Conclusions: The initial SAH involved in an impaired production of pro-inflammatory cytokines in response to LPS with an elevation of plasma epinephrine, dopamine and IL-10 after acute stressful conditions. This phenomenon may play an important role of an early immnosupression in patients with poor grade SAH.

Effect of Selection for Resistance and Susceptibility to Viral Diseases on Concentrations of Dopamine and Immunological Parameters in Six-Week-Old Chickens

White Leghorn chickens were inbred respectively from their parent lines, which were diversely selected for resistance (line 63) or susceptibility (lines 72 and 15I5) to Marek’s disease and lymphoid leukosis. The differences in disease resistance may have been due to differential regulation of immune and neuroendocrine homeostasis. At 5 wk of age, chickens from the same line were randomly assigned to cages at 4 birds per cage. Blood samples were collected from the chickens at 6 wk of age (n = 10/line). Subsets of T lymphocytes (CD4+ and CD8+) and B cells were measured using flow cytometry. Concentrations of plasma IgG and dopamine were quantified with ELISA and HPLC assay, respectively. Line 63 chickens had a higher percentage of CD8+ cells but not CD4+ cells than the chickens of the lines 72 and 15I5 (P < 0.01). In contrast, both lines 72 and 15I5 had a greater percentage of B cells (P < 0.01). The concentrations of plasma IgG and dopamine were also regulated differently among the lines; both were in an order of 72 > 15I5 > 63 (P < 0.05 and P < 0.01, respectively). These results suggested that genetic selection for disease resistance also directly or indirectly modified the corresponding genetic components that govern the immune and neuroendocrine systems. The genetic lines of chickens may be used as animal models for investigation of the cellular mechanisms of genetic-environmental interactions on disease resistance.

Biochemical Markers in the Follow-up of Medullary Thyroid Cancer

Medullary thyroid cancer (MTC) shares biochemical features with other neuroendocrine tumors but the particular characteristics are largely unexplored. We investigated the biochemical neuroendocrine profile of MTC and whether specific markers could be useful in follow-up. In addition to the standard tumor marker calcitonin, plasma carcino-embryonic antigen (CEA), plasma catecholamines, (platelet) serotonin, chromogranin A, tryptase, and urinary markers of catecholamine, histamine, and serotonin metabolism were prospectively determined in 46 patients with histologically proven MTC. Patients were divided according to the stage of disease: group 1, no evidence; group 2, stable disease (SD); and group 3, progressive disease (PD). Plasma dopamine was increased in the majority of the patients with SD and PD; however it did not correlate with extent of disease. Elevated plasma platelet levels of serotonin were only present in patients with multiple endocrine neoplasia 2 with SD or PD but did not differ between those groups. Histamine metabolites were elevated in 20% of patients with SD and PD. In addition to plasma calcitonin, only CEA and chromogranin A could differentiate between stable and progressive MTC. MTCs are capable of synthesizing catecholamines, serotonin, and histamine metabolites underscoring that MTCs have metabolic characteristics in common with other neuroendocrine tumors. Thus far, clinical usefulness and relevance seems limited. The most useful markers in the follow-up of MTC are plasma calcitonin and CEA.

Treatment of post-dialytic orthostatic hypotension with an inflatable abdominal band in hemodialysis patients

The purpose of this study was to ascertain whether abdominal compression with an inflatable abdominal band, a device we developed, improved post-dialytic orthostatic hypotension (OH) in hemodialysis (HD) patients. Twenty-five chronic HD patients with intractable post-dialytic OH were recruited. Post-HD changes in systolic blood pressure (DeltaSBP) in the supine and standing positions were compared in the patients, measured with or without the use of the band. The study showed DeltaSBP after HD without the band was significantly greater than that measured before HD (-36.1+/-18.2 vs -13.1+/-16.8 mm Hg; P<0.0001). DeltaSBP after HD with the band was reduced significantly in comparison to DeltaSBP after HD without the band (-19.4+/-21.2 vs -36.1+/-18.2 mm Hg; P<0.002). Use of the band did not cause an elevation in SBP in the supine position (149.0+/-29.6 vs 155.4+/-25.7 mm Hg); however, it did increase SBP upon standing (129.6+/-27.3 vs 117.2+/-22.6 mm Hg; P<0.05). Eight patients in whom an increase in SBP of 25 mm Hg or more was achieved with the band were classified as responders. Ejection fraction was significantly higher (76.4+/-11.1 vs 61.9+/-13.6%; P<0.02) and atrial natriuretic peptide concentration significantly lower (27.9+/-22.0 vs 68.9+/-47.5 pg/ml; P<0.02) in responders than in non-responders. We conclude that the abdominal band was effective for overcoming post-dialytic OH, without elevating supine SBP in some patients.

Incidental Small Ampullary Somatostatinoma Treated with Ampullectomy 2 Years After Diagnosis

Somatostatinomas are rare tumors; ampullary somatostatinomas are very rare. We report a case of a small pure somatostatin-producing neuroendocrine tumor of ampulla of Vater in a 54-year-old woman with neither neurofibromatosis nor somatostatinoma syndrome, "incidentally" discovered during an abdominal computed tomography. The patient initially refused other adjunctive exams but after 2 years she was admitted, presenting with itch, night sweats, severe fatigue, and unintentional weight loss. The size of the tumor (1.5 cm) and the other radiologic findings had not changed since the abdominal CT scan 2 years before. The somatostatin, gastrin, glucagons, serotonin, vasoactive intestinal peptide, dopamine, norepinephrine, epinephrine, and calcitonin plasma levels were normal. ERCP-obtained biopsies revealed a neuroendocrine tumor with psammoma bodies; immunohistochemical profile was positive for chromogranin and somatostatin. The patient underwent surgery; intraoperative histologic examination of lymph nodes sampling of perihepatic and periduodenal lymph nodes was negative for metastasis. We performed, therefore, a transduodenal ampullectomy. The patient continues to do well at 3 years' follow-up with no evidence of local or distance recurrence of disease.

Dopamine Infusion and Anterior Pituitary Gland Function in Very Low Birth Weight Infants

Background: Previous studies demonstrated that dopamine infusion reduces plasma concentration of thyroxine (T4), thyroid stimulating hormone (TSH), prolactin (PRL), and growth hormone (GH) in adults, children, and infants. Objectives: The purpose of this prospective observational study was to evaluate the relationship between dopamine infusion and the dynamics of T4, TSH, PRL, and GH in preterm newborns weighing less than 1,500 g (very low birth weight infants, VLBW) admitted in a neonatal intensive care unit of a university hospital over a one year period. Methods: A total of 97 preterm newborns were enrolled and divided into two groups: group B included hypotensive infants treated with plasma expanders and dopamine infusion; group A was the control group including newborns who were never treated with dopamine. The newborns were studied dynamically through blood samples taken every day till 10 days. Newborns of group B were studied during dopamine infusion and after its withdrawal. Results: Among the VLBW newborns who were given dopamine, the four pituitary hormones had different dynamics: a reduction of T4, TSH, and PRL levels was noticed since the first day of treatment, and a rebound of their levels was evident since the first day after its interruption. On the contrary, the postprandial GH levels were roughly constant: GH plasma concentrations were in fact a little lower in newborns treated with dopamine, and a slight increase was observed after its withdrawal. However, observed differences were not statistically significant. Conclusions: The results suggest that dopamine infusion reduces T4, TSH, and PRL plasma levels in preterm VLBW infants and have no effect on postprandial GH rate. This hormonal suppression reverses rapidly after dopamine withdrawal. This observation suggests that the iatrogenic pituitary suppression probably cannot produce long-term injuries.

Effects of an environmental enrichment using a drum can on behavioral, physiological and productive characteristics in fattening beef cattle

ABSTRACTTo evaluate the effects of environmental enrichment on behavioral, physiological and productive characteristics, 71 Japanese Black × Holstein steers (8 months of age; 299.5 ± 22.6 kg) were allocated to three pens in two repetitive experiments. Pen C (n = 11 and 12) consisted of a feeding alley for grain feed, a trough for dry hay, a water bowl and a resting space as a control pen. Pen D (n = 12 and 12) included a drum can (58 cm diameter × 90 cm height) containing hay. Pen GD (n = 12 and 12) included a drum can that was placed around artificial plastic turf (30 × 120 cm) for grooming. The drum cans were removed after 5 months of installation. Behavioral observations were made for 2 h at 10 min intervals after feeding on three successive days each month for 10 months. Agonistic interactions were also continuously observed for 1 h after feeding to assess the dominance order (DO). Sampling blood and measuring bodyweight were performed bimonthly. The steers used the drum can frequently for 3 months after installation (1st, 2nd, 3rd months vs 4 months, all P &lt; 0.05). The frequency of total eating of grain feed and hay was higher in pen D and pen GD than in pen C (both P &lt; 0.01), while it was lowest in pen GD after removal of the drum can (P &lt; 0.05). Grooming at the drum can was observed more frequently in pen GD than in pen D (P &lt; 0.05). After they finished eating the grain feed, they ate hay at the drum can that contained additional hay rather than at the trough for hay (P &lt; 0.01). Plasma dopamine concentrations were higher in pen D than in pen C (P &lt; 0.05), and serum triglyceride concentrations were higher in pen C than in pen GD (P &lt; 0.05) during the installation of the drum can. After removal of the drum can, serum total cholesterol concentrations became higher in pen D and GD than in pen C (both P &lt; 0.05). Average daily gain correlated positively with the frequency of eating hay at the drum can in pen D (rs = 0.52, P &lt; 0.01). In pen GD, the frequency of using the drum can correlated negatively with DO (rs = −0.59, P &lt; 0.01). Carcass belly fat was thicker in pens D and GD than in pen C (both P &lt; 0.01). In pen GD, the frequency of eating hay (rs = 0.79, P &lt; 0.01) and grooming at the drum can (rs = 0.63, P &lt; 0.05) correlated positively with the marbling score. Although social factor affected the steers using the drum can, installing it in the early fattening stage encouraged the steers to eat and groom there and resulted in better carcass characteristics through the prolonged physiological positive effects.

Effects of transportation at high ambient temperatures on physiological responses, carcass and meat quality characteristics of three breeds of Omani goats

The experiment was designed to determine the effects of short road transportation in an open truck during the hot season on live weight shrink, physiological responses, carcass, and meat quality characteristics in three breeds of Omani goats. Forty-two male goats (12 months of age) representing equally three breeds of Omani goats (Batina, Dhofari, and Jabal Akhdar) were divided into two groups: 2 h transportation stress (TS) or not transported (NT). The NT group remained unstressed in holding pens with feed and water provided ad libitum prior to slaughter, while the TS group was transported on the day of slaughter 100 km in an open truck. The average temperature during transportation was 37 °C. All animals were blood-sampled before loading and prior to slaughter via jugular venipuncture. Animals were weighed just before loading onto a truck and after transport to assess shrinkage. Muscle shear force, sarcomere length, pH, expressed juice, color, and cooking loss were measured on samples from Mm longissimus dorsi (LD), biceps femoris (BF), and semitendinosus (ST) muscles collected at 24 h postmortem at 1–3 °C. Live weight shrinkage losses were between 1.07 and 1.28 kg. The TS goats had higher plasma cortisol ( P < 0.01), adrenaline, nor-adrenaline, and dopamine concentrations ( P < 0.05) than NS goats. Blood serum from Batina goats had significantly ( P < 0.05) higher cortisol, adrenaline and dopamine and nor-adrenaline concentrations than those from Jabal Akdhar goats. Transportation stress had a significant ( P < 0.05) effect on meat quality characteristics of the LD, BF, and ST muscles. Meat from TS goats had significantly higher ultimate pH, expressed juice, cooking loss percentage, shear force, but significantly lower sarcomere length, L ∗, a ∗, and b ∗ values. LD muscles of Batina goats had significantly higher ultimate pH values and lower L ∗ values than Dhofari and Jabal Akdhar goats. These results indicated that subjecting goats to the 2-hour road transportation with high ambient temperatures can generate major physiological and muscle metabolism responses.

Plasma Catecholamine Levels and Neurobehavioral Problems in Indian Firefighters

Firefighting is a stressful and hazardous job. Persons engaged in firefighting are highly exposed to work-related stress as well as to smoke containing a host of chemicals potentially harmful to human health. In order to elucidate whether firefighting affects neuroendocrine and behavioral responses of firefighters, plasma catecholamine (CA) levels and the prevalence of neurobehavioral symptoms in 62 firefighters (all males, mean age 43 yr) and 52 control subjects matched for age and sex were examined in this study. Self-reported neurobehavioral symptoms data were obtained from a questionnaire survey and personal interview. Concentrations of epinephrine (E), norepinephrine (NE) and dopamine (DA) in plasma were measured by high-performance liquid chromatography with electrochemical detection. Compared with matched controls, the firefighters showed higher prevalence (p<0.05) of neurobehavioral symptoms such as burning sensation in the extremities, tingling and numbness, transient loss of memory, and depression, but no significant difference was recorded in the prevalences of anxiety, vertigo and dizziness. The firefighters demonstrated a more than two-fold (p<0.05) rise in plasma levels of E and NE, but the plasma DA level was relatively unchanged. Controlling age and smoking as possible confounders, firefighting was found to be associated with raised E (OR=2.15; 95% CI, 0.98-4.52), and NE levels (OR=2.24 95% CI, 1.22-3.61). In conclusion, the job of firefighting appears to be associated with stimulation of sympathetic activity and a rise in the prevalence of neurobehavioral symptoms.

A Single Nucleotide Polymorphism at DBH, Possibly Associated with Attention-Deficit/Hyperactivity Disorder, Associates with Lower Plasma Dopamine β-Hydroxylase Activity and is in Linkage Disequilibrium with Two Putative Functional Single Nucleotide Polymorphisms

The DBH gene regulates plasma dopamine beta-hydroxylase activity (pDbetaH). Two single nucleotide polymorphisms (SNPs), -1021C-->T (rs1611115; SNP1) and +1603C-->T (rs6271; SNP3), independently influence pDbetaH. Another SNP, commonly known as DBH Taq1A (rs2519152; SNP2) is associated with attention-deficit/hyperactivity disorder (ADHD) in some (but not all) studies. We tested whether 1) SNP2 associates with pDbetaH; and 2) whether linkage disequilibrium (LD) between SNP2 and the other SNPs explains that association. Plasma dopamine beta-hydroxylase activity and genotypes at the SNPs were determined in Caucasian subjects (n = 418). Associations to pDbetaH were examined using analyses of variance (ANOVAs) and LD among the SNPs using estimation maximization. 1) Each polymorphism analyzed alone associated with pDbetaH; 2) SNP2 was in strong LD with SNP1 and SNP3, respectively, but there was no significant LD between SNP1 and SNP3; and 3) analyzed jointly, each SNP contributed significantly and uniquely to plasma DbetaH activity. 1) SNP2 associates with pDbetaH; 2) SNP2 shows LD with SNP1 and SNP3; 3) most of the association between SNP2 and pDbetaH simply reflects that LD; however, 4) SNP2 also appears to exert a small independent effect on pDbetaH, suggesting that SNP2, or another variant in LD with it, uniquely influences pDbetaH.