Plasma Concentrations Of Dopamine Research Articles

Quantification of Plasma Dopamine in Depressed Patients Using Silver-Enriched Silicon Nanowires as SERS-Active Substrates.

A decrease in the levels of dopamine (DA)─a key catecholamine biomarker for major depressive disorder─highlights the need for quantitative analysis of biological fluids to aid in the early diagnosis of diverse neuropsychiatric disorders. This study developed silicon nanowires enriched with silver nanoparticles to serve as a surface-enhanced Raman scattering (SERS) substrate to enable precise and sensitive quantification of blood plasma DA levels in humans. The silver-enriched silicon nanowires (SiNWs@Ag) yielded flower-like assemblies with densely populated SERS "hot spots," allowing sensitive DA detection. By correlating DA concentration with Raman intensity at 1156 cm-1, the plasma DA levels in treatment-naïve patients with major depression (n = 18) were 2 orders of magnitude lower than those in healthy controls (n = 18) (6.56 × 10-10 M vs 1.43 × 10-8 M). The plasma DA concentrations differed significantly between the two groups (two-tailed p = 5.77×10-7), highlighting a distinct demarcation between depression patients and healthy controls. Furthermore, the SiNWs@Ag substrate effectively differentiated between DA and norepinephrine (NE) in mixtures at nanomolar levels, demonstrating its selective detection capability. This study represents the first report on the quantitative detection of DA levels in human blood samples from individuals with major depression using an SERS technique, emphasizing its potential clinical utility in the evaluation and diagnosis of neuropsychiatric disorders.

A randomized controlled trial to examine the impact of a multi-strain probiotic on self-reported indicators of depression, anxiety, mood, and associated biomarkers.

To examine the efficacy of supplementing with a multi-strain probiotic (MSP) on changes associated with mood, anxiety, and neurotransmitter levels. In a randomized, double-blind, placebo-controlled fashion, 70 healthy men and women (31.0 ± 9.5 years, 173.0 ± 10.4 cm, 73.9 ± 13.8 kg, 24.6 ± 3.5 kg/m2) supplemented with a single capsule of MSP (a total daily dose of 4 × 109 colony forming units [CFU] comprised of a 1 × 109 CFU dose from each of the following strains: Limosilactobacillus fermentum LF16, Lacticaseibacillus rhamnosus LR06, Lactiplantibacillus plantarum LP01, and Bifidobacterium longum 04, Probiotical S.p.A., Novara, Italy) or a maltodextrin placebo (PLA). After 0, 2, 4, and 6 weeks of supplementation and 3 weeks after ceasing supplementation, study participants completed the Beck Depression Inventory (BDI-II), State-Trait Anxiety Inventory (STAI), and Leiden Index of Depression Sensitivity (LEIDS-R) questionnaires and had plasma concentrations of cortisol, dopamine, serotonin, and C-reactive protein determined. BDI, STAI, and total LEIDS-R scores were reduced from baseline (p < 0.05) with MSP supplementation after 4 and 6 weeks of supplementation and 3 weeks after supplementation while no changes (p > 0.05) were reported in PLA. When compared to PLA, MSP scores for state anxiety, trait anxiety, and LEIDS-R (hopeless, aggression, rumination, and total score) were significantly lower (p < 0.05) after supplementation. Plasma serotonin concentrations in MSP were increased from baseline after 6 weeks of supplementation and 3 weeks after ceasing supplementation. No changes (p > 0.05) in plasma dopamine, C-reactive protein, or cortisol concentrations were observed between groups. MSP supplementation resulted in widespread improvements in several questionnaires evaluating mood, anxiety, and depression in young, healthy men and women. MSP supplementation increased serotonin increased after 6 weeks of MSP supplementation with no change in dopamine, C-reactive protein, or cortisol. https://classic.clinicaltrials.gov/ct2/show/NCT05343533, NCT05343533.

Abnormally high expression of D1-like dopamine receptors on lupus CD4+ T cells promotes Tfh cell differentiation

ObjectiveSLE is a chronic autoimmune disease that places a great burden on human society. T follicular helper (Tfh) cells play a critical role in the pathological process of SLE. Therefore,...

Exogenous ketosis increases circulating dopamine concentration and maintains mental alertness in ultra-endurance exercise.

Exogenous ketosis can improve psychocognitive functioning during exercise as well as stimulate postexercise muscular recovery. Therefore, we hypothesized that ketone ester (KE) supplementation can counteract the decline in psychocognitive functioning during ultra-endurance exercise and stimulate muscular recovery. Eighteen recreational runners participated in a full 100 km trail run (RUN, n = 8), or ran to premature exhaustion (80 km: n = 6; 60 km: n = 4). Before (25 g), during (25 g·h-1), and after (5 × 25 g in 24 h) RUN they received ketone ester (R)-3-hydroxybutyl (R)-3-hydroxybutyrate (KE, n = 9) supplements or a noncaloric placebo (CON, n = 9). Blood samples and muscle biopsies were taken, and mental alertness was assessed by a psychocognitive test battery at different times before, during, and up to 36 h after RUN. Compared with CON (<0.3 mM), in KE blood d-β-hydroxybutyrate concentration was consistently elevated to ∼2-3 mM during RUN. In CON, RUN increased visual reaction times from 353 ± 53 to 419 ± 54 ms, and movement execution times from 174 ± 47 to 245 ± 64 ms. But this effect was fully negated by KE (P < 0.05). Plasma dopamine concentrations doubled in KE during RUN but remained stable in CON, resulting in higher concentrations after RUN in KE (4.1 ± 1.7 nM) than in CON (2.4 ± 0.8 nM, P = 0.048). KE also inhibited muscular infiltration of macrophages and suppressed AMPK phosphorylation status until 36-h postexercise (P < 0.05 KE vs. CON). In conclusion, KE increases circulating dopamine concentration and improves mental alertness, as well as improves postexercise muscular inflammation in ultra-endurance exercise.NEW & NOTEWORTHY Oral ketone ester ingestion elevates circulating dopamine concentration during ultra-endurance exercise. This is associated with improved mental alertness. Furthermore, ketone ester intake inhibits postexercise skeletal muscle macrophage infiltration, and counteracts the increase in AMPK phosphorylation after exercise, which indicates improved muscular energy status.

Relationship between plasma dopamine concentration and temperament in horses

Dopamine (DA) is a neurotransmitter associated with animal behaviors. Along with other neurotransmitters such as oxytocin (OXT) and serotonin (5-HT), DA is also involved in determining the temperament of animals. However, the involvement of DA in horse temperament has not been well elucidated. Therefore, in this study, we aimed to determine the correlation between plasma DA concentration and OXT and 5-HT concentrations and behavioral temperament (eg, docility and friendliness, fearfulness, dominance, and trainability) of horses. Blood samples were collected from 31 horses and the concentrations of DA, OXT, and 5-HT were measured using enzyme-linked immunosorbent assay. The temperament of horses was assessed and scored by 3 researchers. The correlation between the plasma concentration of DA and OXT or 5-HT was statistically analyzed using SPSS software and linear regression analysis was performed to determine the association between DA concentration and OXT and 5-HT concentrations. Meanwhile, the DA concentration associated with each type of temperament was analyzed via one-way analysis of variance with LSD post hoc analysis as well as Student's t-test (for trainability). Plasma DA concentration was not found to be correlated with either OXT or 5-HT concentrations. Furthermore, we found no correlation between plasma DA concentration and dominance and trainability. However, our results suggest the possibility of predicting the degree of fearfulness of horses using plasma DA concentrations. We conclude that plasma DA concentration has a potentiality to be used as a biomarker to predict the fearfulness of horses.

A Study of Dopaminergic Pathway in Neurologic Wilson Disease with Movement Disorder

Movement disorder (MD) is an important manifestation of neurologic Wilson disease (NWD), but there is a paucity of information on dopaminergic pathways. We evaluate dopamine and its receptors in patients with NWD and correlate the changes with MD and MRI changes. Twenty patients with NWD having MD were included. The severity of dystonia was assessed using BFM (Burke-Fahn-Marsden) score. The neurological severity of NWD was categorized as grades I to III based on the sum score of 5 neurological signs and activity of daily living. Dopamine concentration in plasma and CSF was measured using liquid chromatography-mass spectrometry, and D1 and D2 receptor expression at mRNA by reverse transcriptase polymerase chain reaction in patients and 20 matched controls. The median age of the patients was 15years and 7 (35%) were females. Eighteen (90%) patients had dystonia and 2 (10%) had chorea. The CSF dopamine concentration (0.08 ± 0.02 vs 0.09 ± 0.017pg/ml; p = 0.42) in the patients and controls was comparable, but D2 receptor expression was reduced in the patients (0.41 ± 0.13 vs 1.39 ± 1.04; p = 0.01). Plasma dopamine level correlated with BFM score (r = 0.592, p < 0.01) and D2 receptor expression with the severity of chorea (r = 0.447, p < 0.05). The neurological severity of WD correlated with plasma dopamine concentration (p = 0.006). Dopamine and its receptors were not related to MRI changes. The central nervous system dopaminergic pathway is not enhanced in NWD, which may be due to structural damage to the corpus striatum and/or substantia nigra.

Improvement of several stress response and sleep quality hormones in men and women after sleeping in a bed that protects against electromagnetic fields

BackgroundThe electromagnetic fields (EMFs) emitted by the technologies affect the homeostatic systems (nervous, endocrine, and immune systems) and consequently the health. In a previous work, we observed that men and women, after 2 months of using a bed with a registered HOGO system, that prevents and drain EMFs, improved their immunity, redox and inflammatory states and rejuvenated their rate of aging or biological age. Since, EMFs can act as a chronic stressor stimulus, and affect the sleep quality. The objective of this work was to study in men and women (23–73 years old) the effect of sleeping for 2 months on that bed in the blood concentrations of several hormones related to stress response and sleep quality as well as to corroborate the rejuvenation of their biological age.MethodsIn 18 men and women, plasma concentration of cortisol, dehydroepiandrosterone (DHEA), catecholamines (epinephrine, norepinephrine and dopamine), serotonin, oxytocin and melatonin were analyzed before and after 2 months of using the HOGO beds. A group of 10 people was used as placebo control. In another cohort of 25 men (20 experimental and 5 placebo), the effects of rest on the HOGO system on the concentration of cortisol and testosterone in plasma were studied. In all these volunteers, the biological age was analyzed using the Immunity Clock model.ResultsThere is a significant increase in plasma concentration of DHEA, norepinephrine, serotonin, oxytocin, and melatonin as well as in testosterone, after resting for 2 months in that bed with the EMFs avoiding system. In addition, decreases in Cortisol/DHEA and Testosterone/cortisol ratio and plasma dopamine concentration were observed. No differences were found in placebo groups. In all participants that slept on HOGO beds, the biological age was reduced.ConclusionsSleeping in a bed that isolates from EMFs and drain them can be a possible strategy to improve the secretion of hormones related to a better response to stress and sleep quality, which means a better endocrine system, and consequently better homeostasis and maintenance of health. This fact was confirmed with the slowdown in the rate of aging checked with a rejuvenation of the biological age.

Plasma concentration of dopamine varies depending on breed, sex, and the genotype of DRD4 in horses.

Dopamine (DA) is known to be a key modulator of animal behaviors. Thus, the plasma concentration of DA might be used as a biomarker for the behavioral characteristics of horses. The behavioral characteristics of horses vary depending on the breed, age, and sex. Moreover, the DA receptor genotypes are also related to horse behaviors. Thus, the aim of this study was to investigate the DA concentration variations of horse plasma by breed, age, sex, or genotype of its receptor. The horses were divided by breed into Thoroughbred (n = 13), Pony (n = 9), Warmblood (n = 4), and Haflinger (n = 5). The age variable was divided into three different groups: post-pubertal (2–5 years, n = 6), adult (6–13 years, n = 19), and aged horses (15–24 years, n = 6). The sex variable was divided into geldings (n = 8) and mares (n = 23). Approximately 10 mL of blood was collected, and an ELISA kit was used to measure the plasma concentration of DA. Polymerase chain reaction analysis was performed to identify the genetic variation in the DA D4 receptor gene (DRD4). SPSS statistical software was used for statistical analysis. The DA concentrations in geldings were significantly lower than those in mares. There was no significant difference in DA concentrations among breed and age groups. Horses with the GG and GA genotypes had significantly higher plasma concentrations of DA compared to horses with the AA genotype for the G292A gene. Briefly, the plasma concentration of DA varied depending on the sex and genotype of G292A. These factors should be considered when the concentration of DA is used as a biomarker for the behavioral characteristics of horses. In conclusion, the DA concentration or DRD4 genotype of horse plasma has the potential to be used as a biomarker that can predict the behavioral characteristics of horses.

Perioperative Supplemental Oxygen and Plasma Catecholamine Concentrations after Major Abdominal Surgery-Secondary Analysis of a Randomized Clinical Trial.

Perioperative stress is associated with increased sympathetic activity that leads to increases in heart rate and blood pressure, which are associated with the development of perioperative myocardial ischemia. In healthy volunteers, it was shown that the administration of supplemental oxygen attenuated sympathetic nerve activity and subsequently led to lower plasma catecholamine concentrations. We therefore tested the hypothesis that perioperative supplemental oxygen attenuates sympathetic nerve in patients at risk for cardiovascular complications undergoing major abdominal surgery. We randomly assigned 81 patients to receive either 80% or 30% inspired oxygen concentration throughout surgery and the first two postoperative hours. We assessed noradrenaline, adrenaline, and dopamine plasma concentrations before the induction of anesthesia, two hours after surgery and on the third postoperative day. There was no significant difference in postoperative noradrenaline (effect estimated: −41.5 ng·L−1, 95%CI −134.3, 51.2; p = 0.38), adrenaline (effect estimated: 11.2 ng·L−1, 95%CI −7.6, 30.1; p = 0.24), and dopamine (effect estimated: −1.61 ng·L−1, 95%CI −7.2, 3.9; p = 0.57) concentrations between both groups. Based on our results, it seems unlikely that supplemental oxygen influences endogenous catecholamine release in the perioperative setting.

Effect of liver resection-induced increases in hepatic venous pressure gradient on development of postoperative acute kidney injury

BackgroundThe impact of changes in portal pressure before and after liver resection (defined as ΔHVPG) on postoperative kidney function remains unknown. Therefore, we investigated the effect of ΔHVPG on (i) the incidence of postoperative AKI and (ii) the renin-angiotensin system (RAAS) and sympathetic nervous system (SNS) activity.MethodsWe included 30 patients undergoing partial liver resection. Our primary outcome was postoperative AKI according to KDIGO criteria. For our secondary outcome we assessed the plasma renin, aldosterone, noradrenaline, adrenaline, dopamine and vasopressin concentrations prior and 2 h after induction of anaesthesia, on the first and fifth postoperative day. HVPG was measured prior and immediately after liver resection.ResultsΔHVPG could be measured in 21 patients with 12 patients HVPG showing increases in HVPG (∆HVPG≥1 mmHg) while 9 patients remained stable. AKI developed in 7/12 of patients with increasing HVPG, but only in 2/9 of patients with stable ΔHVPG (p = 0.302). Noradrenalin levels were significantly higher in patients with increasing ΔHVPG than in patients with stable ΔHVPG. (p = 0.009). Biomarkers reflecting RAAS and SNS activity remained similar in patients with increasing vs. stable ΔHVPG.ConclusionsPatients with increased HVPG had higher postoperative creatinine concentrations, however, the incidence of AKI was similar between patients with increased versus stable HVPG.

Effects of phytase supplementation and increased nutrient density on growth performance, carcass characteristics, and hypothalamic appetitive hormone expression and catecholamine concentrations in broilers from 1 to 43 days of age

Two experiments were conducted to evaluate extra-phosphoric effects of phytase and nutrient density on growth performance, meat yield, and hypothalamic appetitive hormone expression and catecholamine concentrations of broilers. Experiment 1 determined differences of digestible amino acid concentrations and AMEn using 256 Yield Plus × Ross 708 broilers (32 cages, 8 birds/cage) fed diets without or with 4,500 phytase units (FTU)/kg inclusion (16 reps/treatment). In Experiment 2, 832 Yield Plus × Ross 708 broilers (32 pens; 26 birds/pen) were provided diets in a 2 × 2 factorial arrangement consisting of 2 nutrient contents (without or with increased density) and 2 phytase inclusions (0 or 4,500 FTU/kg). Increased nutrient density was formulated to contain 0.007, 0.015, 0.013, 0.021, 0.024%, and 61 kcal/kg higher digestible SAA, Lys, Thr, Val, Ile, and AMEn (from Experiment 1) respectively, compared with the control diet. Growth performance was determined at 14, 28, and 40 d of age and carcass characteristics at 41 d of age. At 43 d of age, plasma inositol, hypothalamic appetitive hormone expression, and catecholamine concentrations were determined from 4 birds/pen. Additive effects of phytase inclusion and increased nutrient density resulted in the lowest (P < 0.05) feed conversion from 1 to 40 d of age and the heaviest (P < 0.01) breast meat weights among dietary treatments. Phytase addition numerically increased feed intake (P = 0.06) and BW gain (P = 0.051) compared with birds fed diets without phytase from 1 to 40 d of age. Plasma inositol and dopamine concentrations were 2.3- and 1.2-fold higher (P < 0.01), respectively, in broilers fed phytase-added diets than birds fed diets without phytase inclusion. However, mRNA expression of neuropeptide Y, agouti-related peptide, proopiomelanocortin, cholecystokinin A receptor, ghrelin, and serotonin concentration were not different (P > 0.05) among treatments. These data indicated additive effects of phytase supplementation and increased nutrient density on growth performance and meat accretion of broilers. However, the influence of phytase on feed intake warrants future research.

Sympathetic Nervous System Activity in Patients with Metabolic Syndrome, Type 2 Diabetes Mellitus and Chronic Kidney Disease. Role of Renalase and Alpha Amylase

Aim: To evaluate serum renalase and salivary alpha amylase concentrations and their relationship with plasma catecholamine levels in patients with Metabolic Syndrome (MS), Type 2 Diabetes Mellitus (T2DM), and End-Stage Renal Disease (ESRD). Method: In cross-sectional study 163 patients were enrolled; 43 patients with MS, 93 withT2DM, 13 with ESRD, and 14 healthy subjects (control group). All patients had their ascription to the UMAA/UMF No. 75, in Morelia, Michoacan, Mexico. Glucose, creatinine, cholesterol, triglycerides, HDL, and renalase were measurement in serum, and Dopamine (DA), Epinephrine (E) and Norepinephrine (NE) in plasma. An aliquot of saliva was collected for alpha amylase determination. Results: High plasma concentrations of DA, E and NE (p&lt;0.0001) was founded in T2DM and ESRD patients. Renalase was lower in ESRD compared to MS and T2DM patients (p&lt;0.0001). High concentrations of alpha amylase were found in MS, T2DM, and ESRD patients in comparison with control group (p&lt;0.0001). Catecholamines correlated positively with alpha amylase and diabetes evolution. Conclusion: Sympathetic hyperactivity in MS, T2DM and ESRD patients was founded. Renalase could be proposed as biomarker of renal function and salivary alpha amylase as sympathetic hyperactivity. Additional studies are required to evaluate the pathophysiological mechanisms involved of SNS in CKD development.

Clinical presentation and long-term follow-up of dopamine beta hydroxylase deficiency.

Dopamine beta hydroxylase (DBH) deficiency is an extremely rare autosomal recessive disorder with severe orthostatic hypotension, that can be treated with L‐threo‐3,4‐dihydroxyphenylserine (L‐DOPS). We aimed to summarize clinical, biochemical, and genetic data of all world‐wide reported patients with DBH‐deficiency, and to present detailed new data on long‐term follow‐up of a relatively large Dutch cohort. We retrospectively describe 10 patients from a Dutch cohort and 15 additional patients from the literature. We identified 25 patients (15 females) from 20 families. Ten patients were diagnosed in the Netherlands. Duration of follow‐up of Dutch patients ranged from 1 to 21 years (median 13 years). All patients had severe orthostatic hypotension. Severely decreased or absent (nor)epinephrine, and increased dopamine plasma concentrations were found in 24/25 patients. Impaired kidney function and anemia were present in all Dutch patients, hypomagnesaemia in 5 out of 10. Clinically, all patients responded very well to L‐DOPS, with marked reduction of orthostatic complaints. However, orthostatic hypotension remained present, and kidney function, anemia, and hypomagnesaemia only partially improved. Plasma norepinephrine increased and became detectable, while epinephrine remained undetectable in most patients. We confirm the core clinical characteristics of DBH‐deficiency and the pathognomonic profile of catecholamines in body fluids. Impaired renal function, anemia, and hypomagnesaemia can be part of the clinical presentation. The subjective response to L‐DOPS treatment is excellent and sustained, although the neurotransmitter profile in plasma does not normalize completely. Furthermore, orthostatic hypotension as well as renal function, anemia, and hypomagnesaemia improve only partially.

Unreliability of EDTA samples for measuring bioamine neurotransmitter levels in cats.

The aim of this study was to assess the reliability of an EDTA-based method for measuring cat blood bioamines. Test 1 involved collecting blood samples from seven university laboratory cats. The samples were transferred to EDTA, heparin and plain tubes to determine concentrations of four bioamines (serotonin, dopamine, epinephrine [adrenaline] and norepinephrine [noradrenaline]). Correlation of measurements performed on EDTA plasma, with those performed on heparinized plasma or serum were assessed by intraclass correlation coefficients (ICCs). In test 2, blood samples from five owned cats were collected and stored in EDTA tubes and divided between duplicate Eppendorf tubes labeled as different cats for blinding purposes and analyzed independently for the same four bioamines as in test 1. Reliability of concentration determination for these duplicates was assessed by ICCs and coefficients of variation (CVs). In test 1, there was no significant correlation between the EDTA plasma serotonin and serum serotonin concentrations. There was also no significant correlation between EDTA plasma and heparin plasma concentrations for either epinephrine or norepinephrine. There was a statistically significant but weak correlation between EDTA plasma and heparin plasma dopamine concentrations. In test 2, there was no correlation for repeat-analyzed serotonin and epinephrine concentrations. Although there were statistically significant correlations for dopamine and norepinephrine, CVs for each analyte were in excess of 30%. Before any further attempt is made to measure and report on neurotransmitter concentrations in domestic cats, it is essential that the robustness of the methodology is carefully validated and the data presented.

Dietary phytase and myo-inositol supplementation are associated with distinct plasma metabolome profile in broiler chickens

Phytase enzyme is used as a dietary supplement in broiler nutrition to improve phosphorous bioavailability. Phytase deliberates phosphate groups from phytic acid and produces myo-inositol after total dephosphorylation. Myo-inositol is a bioactive compound having beneficial modulatory effects on metabolism in humans. However, it is not well understood if and how phytic acid degradation products, particularly myo-inositol, can modulate metabolism in broiler chicken. The purpose of this study was to investigate effects of dietary supplements of phytase and myo-inositol on the blood plasma metabolome profile of broiler chickens. Broilers were provided a nutrient-adequate control diet or the same diet supplemented with either 3.5 g myo-inositol or 500, 1500 or 3000 units of phytase, per kilogram of feed (grower diet). Broilers were group-housed in floor pens (eight pens per diet) and provided one of the treatment diets for 22 days. Then, blood was collected from one bird per pen, resulting in eight replicated measurements per diet. A targeted metabolomics approach was applied to the heparin plasma. Body weight of the birds was not significantly affected by the treatments. Plasma myo-inositol concentrations were significantly increased by myo-inositol supplementation and phytase supplementation at 500 and 1500 units/kg. Metabolites generally affected by phytase supplementation belonged to the groups of acyl-carnitines, phosphatidylcholines, sphingomyelins, lysophosphatidylcholine, biogenic amines and amino acids. Compared to the control diet, phytase supplements had significantly higher plasma concentrations of kynurenine and creatinine, but lower concentrations of histamine and cis-4-hydroxyproline. Myo-inositol supplementation significantly increased plasma concentrations of dopamine and serotonine. While some metabolites were similarly affected by myo-inositol and phytase supplementation, others were distinctly differently affected. We conclude that myo-inositol, either as a directly added supplement or indirectly released from phytate upon phytase supplementation, can affect specific metabolic pathways. Additional effects found on phytase supplementation may be related to intermediary phytate degradation products. Results are indicative for innovative hypothesis to be tested in future experiments, for instance, with regard to relationships between phytase or myo-inositol supplements and bird immunity or behaviour.

Plasma dopamine concentrations following dopamine infusion to isoflurane-anesthetized New Zealand White rabbits

ObjectiveTo determine the pharmacokinetics of dopamine following a short infusion in isoflurane-anesthetized rabbits. Study designProspective, descriptive pharmacokinetic study. AnimalsA group of six adult female New Zealand White rabbits weighing 4.4 ± 0.2 kg. MethodsRabbits were anesthetized with isoflurane in oxygen and maintained at 1.2 × minimum alveolar concentration of isoflurane (2.3% atmosphere). Dopamine (30 μg kg–1 minute–1) was infused for 10 minutes. Arterial blood was sampled prior, during and following the infusion at various intervals for 1 hour. ResultsA one-compartment model with baseline concentration best fitted the time–plasma dopamine concentration data. Estimated typical population value (interindividual variability) for volume of distribution and clearance were 10.3 (232%) L kg–1 and 9.9 (508%) L minute–1 kg–1, respectively. Conclusions and clinical relevanceThere was a large degree of interindividual variation in the disposition of dopamine. The large volume of distribution and high metabolic clearance rate reported for dopamine in this study likely explains the lack of clinical efficacy of dopamine in rabbits at doses up to 30 μg kg–1 minute–1.

Monoamine oxidase polymorphisms in rhesus and Japanese macaques (Macaca mulatta and M. fuscata)

Monoamine oxidase A (MAO-A) and monoamine oxidase B (MAO-B) are enzymes that degrade several monoamines of the central nervous system and have long been implicated in the modulation of social behavior. Macaque monkeys are a suitable model for investigating the role of functional monoamine oxidase polymorphisms in behavior modulation given the high amount of social diversity among the nearly two dozen species. The present study reports allele frequencies for two polymorphisms, MAOA-LPR and MBin2, in samples of rhesus (Macaca mulatta) and Japanese (M. fuscata) macaques. Our results suggest that the two species may differ in high- and low-activity MAOA-LPR allele frequencies. Specifically, 89% of the Japanese macaque alleles in our sample were the low-activity variant, whereas only 41% of the rhesus macaque alleles were of this sort. In our samples, the two species possessed similar allelic variation at the MBin2 locus, with each possessing some species-specific alleles. We also tested for associations between MAOA-LPR genotype and plasma serotonin (5-HT) and dopamine (DA) concentrations in a subset of rhesus macaques, which revealed no association with genotype. Our findings point toward potential differences in the monoaminergic system of two closely related macaque species. Discussion of our results are centered on implications for future investigations that aim to better understand the functionality of monoamine oxidase polymorphisms in the context of primate social behavior.

Protective effects of blueberry drink on cognitive impairment induced by chronic mild stress in adult rats.

BACKGROUND/OBJECTIVESStress-induced cognitive impairment is related to the suppression of hippocampal neurogenesis that results from an increase of oxidative stress. Therefore, the aim of this study was to investigate the effects of administration of a blueberry drink, having a high antioxidant power, on the cognitive performance of adult rats exposed to chronic mild stress.MATERIALS/METHODSTwelve-week-old male Sprague-Dawley rats (n = 48) were randomly divided into four groups: control (CO), stress (ST), control + 5% blueberry drink (CO + B), and stress + 5% blueberry drink (ST + B). After eight weeks, the cognitive performance was assessed using a multiple T-maze water test. Levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and ascorbic acid were measured in the brain, and catecholamine concentrations were measured in plasma.RESULTSThe brain weights of the rats from the ST and ST + B groups were significantly lower than those of the rats from the CO and CO + B groups. The cognitive performance of the ST group was impaired when compared to that of the CO group. This impairment was significantly improved by the blueberry drink supplementation (P < 0.05). The brain SOD and CAT concentrations were not influenced by the stress or by the blueberry drink. However, the brain levels of GPx and ascorbic acid were significantly lower in the ST group than those in the CO group and were increased by the blueberry drink supplementation. The plasma catecholamine concentrations were affected by chronic mild stress and by the blueberry drink. The plasma norepinephrine and dopamine concentrations were decreased by the chronic stress and improved by the blueberry drink supplementation. The plasma epinephrine level was only influenced by the stress.CONCLUSIONThese findings suggest that the blueberry drink may protect against the cognitive impairment induced by chronic mild stress.

Neuroendocrine Response To Heated Water-based Exercise Training On Resistant Hypertensive Patients

PURPOSE: Heated water based EXercise training (HEx) is a new alternative intervention in cardiac rehabilitation, and it has been studied about its effects on cardiovascular adaptations; but still there is no data about neuroendocrine effects of this training. This study examines the effects of HEx on neuroendocrine response in resistant hypertensive patients. METHODS: This is a parallel, randomized controlled trial. 125 nonconsecutive sedentary patients with resistant hypertension from a hypertension outpatient clinic in a university hospital were screened; 44 patients fulfilled the study requirements and had their blood analyzed for the concentration of plasma catecholamines (dopamine, adrenaline and noradrenaline), endothelin -1, nitric oxide (NO), plasma aldosterone concentration and plasma renin activity (PRA) than the patients were divided in two groups, one group was trained in a heated pool (32oC) for 12 weeks, 3 times a week; and the other group was the control group. The sessions were performed for 60 minutes and were consisted of callisthenic exercises and walking inside the pool. The control group was asked to maintain habitual activities. After 12 weeks all patients repeated the blood tests. RESULTS: 44 patients (HEx n=28; control n=16) were randomized; there was no loss during the follow-up and no adverse events occurred during the study. HEx decreased plasma concentration of dopamine (from 145±88 to 26±21 ng/ml, p<0.0001), adrenaline (from 353±156 to 169±93 ng/ml, p=0.009), noradrenaline (from 720±255 to 307±137 ng/ml, p=0.001), andothelin-1 (from 42±14 to 26±8 pg/ml, p=0.003), aldosterone (from 94±48 to 77±22 pg/ml, p=0.006) PRA (from 35±14 to 3±3 mmHg ng/ml/H, p<0.0001); and increased NO (from 25±7 to 77±22 uM, p= 0.001).The control group after 12 weeks did not have any changes on blood analysis results. CONCLUSIONS: HEx was able to improve important neuroendocrine adaptations in resistant hypertensive patients. These effects suggest that HEx may be a potential new therapeutic approach in these patients.

Effects of the transportation during hot season and electrical stimulation on meat quality characteristics of goat Longissimus dorsi muscle

A factorial experimental design was used to study the effects of transportation during the hot season and low voltage electrical stimulation (90V) on physiological, and meat quality characteristics of goats. Twenty male Dhofari goats (12-month old) were divided into two treatment groups: transported for 6h during hot season (42°C day time temperature) or non-transported. Goats were blood-sampled before loading for transportation and prior to slaughter. Five carcasses from each group were randomly electrically stimulated for 60s, nearly 20min postmortem using V1.3-R3B stimulator (7.5ms duration positive pulses only and an output of 90–95V, AgResearch, New Zealand). Ultimate pH, shear force, sarcomere length, myofibrillar fragmentation index, expressed juice, cooking loss and CIE L*, a* and b* color were measured on samples from Longissimus dorsi muscles. The transported goats had higher plasma cortisol (P<0.01), adrenaline, nor-adrenaline and dopamine concentrations (P<0.05) than non-transported goats. Transportation and electrical stimulation for 6h had a significant effect on quality characteristics of meat. Muscles from electrically stimulated carcasses had significantly (P<0.05) lower ultimate pH values (5.68 vs. 5.84), longer sarcomeres (1.67μm vs. 1.46μm), lower shear force values (5.05kg vs. 8.35kg), higher expressed juice (39.5 vs. 37.45) and myofibrillar fragmentation index (MFI) (77.25 vs. 71.45) than those from non-stimulated ones. Electrically stimulated meat had significantly (P<0.05) lighter color than non-stimulated meat based on L* value. Meat from transported goats had significantly higher ultimate pH (5.84 vs. 5.67), expressed juice (40.2 vs. 36.8), shear force (7.85kg vs. 5.55kg), but significantly lower sarcomere length (1.53μm vs. 1.60μm). This study indicated that transporting goats for 6h during hot season can cause physiological responses and deteriorate meat quality characteristics. Applying low voltage electrical stimulation may reduce negative effects of transportation on meat quality characteristics of goats.