Sustained Action of Developmental Ethanol Exposure on the Cortisol Response to Stress in Zebrafish Larvae and Adults

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedThis study was supported by the National Centre for the replacement, refinement and reduction of animals in research

Modulation of Brain β-Endorphin Concentration by the Specific Part of the Y Chromosome in Mice

International audienceBackground: Several studies in animal models suggest a possible effect of the specific part of the Y-chromosome (Y NPAR) on brain opioid, and more specifically on brain b-endorphin (BE). In humans, male prevalence is found in autistic disorder in which observation of abnormal peripheral or central BE levels are also reported. This suggests gender differences in BE associated with genetic factors and more precisely with Y NPAR. Methodology/Principal Findings: Brain BE levels and plasma testosterone concentrations were measured in two highly inbred strains of mice, NZB/BlNJ (N) and CBA/HGnc (H), and their consomic strains for the Y NPAR. An indirect effect of the Y NPAR on brain BE level via plasma testosterone was also tested by studying the correlation between brain BE concentration and plasma testosterone concentration in eleven highly inbred strains. There was a significant and major effect (P,0.0001) of the Y NPAR in interaction with the genetic background on brain BE levels. Effect size calculated using Cohen's procedure was large (56% of the total variance). The variations of BE levels were not correlated with plasma testosterone which was also dependent of the Y NPAR. Conclusions/Significance: The contribution of Y NPAR on brain BE concentration in interaction with the genetic background is the first demonstration of Y-chromosome mediated control of brain opioid. Given that none of the genes encompassed by the Y NPAR encodes for BE or its precursor, our results suggest a contribution of the sex-determining region (Sry, carried by Y NPAR) to brain BE concentration. Indeed, the transcription of the Melanocortin 2 receptor gene (Mc2R gene, identified as the proopiomelanocortin receptor gene) depends on the presence of Sry and BE is derived directly from proopiomelanocortin. The results shed light on the sex dependent differences in brain functioning and the role of Sry in the BE system might be related to the higher frequency of autistic disorder in males

Pain Reactivity and Plasma β-Endorphin in Children and Adolescents with Autistic Disorder

International audienceBackground: Reports of reduced pain sensitivity in autism have prompted opioid theories of autism and have practical care ramifications. Our objective was to examine behavioral and physiological pain responses, plasma β-endorphin levels and their relationship in a large group of individuals with autism.Methodology/Principal Findings: The study was conducted on 73 children and adolescents with autism and 115 normal individuals matched for age, sex and pubertal stage. Behavioral pain reactivity of individuals with autism was assessed in three observational situations (parents at home, two caregivers at day-care, a nurse and child psychiatrist during blood drawing), and compared to controls during venepuncture. Plasma β-endorphin concentrations were measured by radioimmunoassay. A high proportion of individuals with autism displayed absent or reduced behavioral pain reactivity at home (68.6%), at day-care (34.2%) and during venepuncture (55.6%). Despite their high rate of absent behavioral pain reactivity during venepuncture (41.3 vs. 8.7% of controls, P<0.0001), individuals with autism displayed a significantly increased heart rate in response to venepuncture (P<0.05). Moreover, this response (Δ heart rate) was significantly greater than for controls (mean±SEM; 6.4±2.5 vs. 1.3±0.8 beats/min, P<0.05). Plasma β-endorphin levels were higher in the autistic group (P<0.001) and were positively associated with autism severity (P<0.001) and heart rate before or after venepuncture (P<0.05), but not with behavioral pain reactivity.Conclusions/Significance: The greater heart rate response to venepuncture and the elevated plasma β-endorphin found in individuals with autism reflect enhanced physiological and biological stress responses that are dissociated from observable emotional and behavioral reactions. The results suggest strongly that prior reports of reduced pain sensitivity in autism are related to a different mode of pain expression rather than to an insensitivity or endogenous analgesia, and do not support opioid theories of autism. Clinical care practice and hypotheses regarding underlying mechanisms need to assume that children with autism are sensitive to pain

Effect of CDP-choline on Hippocampal Acetylcholinesterase and Na+,K+-ATPase in Adult and Aged Rats

The aim of this study was to investigate the effect of different cytidine-5′-diphosphocholine (CDP-choline) concentrations (0.1-1 mm) on acetylcholinesterase (AChE), (Na+,K+)-ATPase and Mg2+-ATPase activities in homogenates of adult and aged rat hippocampi. Tissues were homogenised, centrifuged at 1000 x g for 10 min and in the supernatant, AChE activity and Na+,K+-ATPase and Mg2+-ATPase activities were determined according to Ellman&apos;s method and Bowler&apos;s and Tirri&apos;s method, respectively. After an 1-3 h preincubation of the homogenised tissue with CDP-choline, a maximal AChE stimulation of about 25% for both adult and aged rats (p &amp;lt; 0.001) and a Na+,K+-ATPase activation of about 50% for adult rats (p &amp;lt; 0.001) and about 60% for aged rats (p &amp;lt; 0.001) were observed, while hippocampal Mg2+-ATPase activity was not influenced in either adult or aged animals. It is suggested that: CDP-choline can restore hippocampal AChE and Na+,K+-ATPase activities in the aged rat and thus it may play a role in improving memory performance which is impaired by aging and some neuronal disturbances. © 1946–2014, Verlag der Zeitschrift für Naturforschung. All rights reserved

Effect of Aging on the Activities of Acetylcholinesterase, Na+, K+-ATPase and Mg2+-ATPase in Rat Pituitary and Hypothalamus

Aging, Rat Pituitary, Rat Hypothalamus, Acetylcholinesterase, Na+,K+-ATPase, Mg2+-ATPase Acetylcholinesterase (AChE). Na+, K+-ATPase and Mg2+-ATPase activities were estimated in homogenised rat pituitary and hypothalamus of 4- and 22-month-old rats. AChE activity was not altered in the pituitary of aged compared to adult rats, while it was found decreased by about 40% in the hypothalamus. Na+,K+-ATPase activity remained stable in the hypothalamus, while it was decreased by about 38% in the pituitary. Mg2+-ATPase activity remained unchanged in the hypothalamus, but was increased by about 83% in the pituitary. This pituitary Na+, K+-ATPase inactivation may result in pathological mood and decreased neural excitability and metabolic energy production in aged animals. The agerelated alterations of AChE, Na+, K+-ATPase and Mg2+-ATPase activities may reflect changes in secretion and responses of some hormones of pituitary and hypothalamus. © 1998, Verlag der Zeitschrift für Naturforschung. All rights reserved

Effect of CDP-choline on brain acetylcholinesterase and Na+,K+-ATPase in adult rats

Objective: The aim of this work was to investigate the effect of different cytidine-5’-diphosphocholine (GDP-choline) concentrations(0.1-1 mM) on acetylcholinesterase (AChE), (Na+,K+)-ATPase and Mg2+-ATPase activities in homogenates of adult rat whole brain and in pure (nonmembrane bound) enzymes. Design and Methods: Tissues were homogenized, centrifuged at 1000 X g for 10 min, and in the supernatant AChE activity and Na+,K+-ATPase, Mg2+-ATPase activities were determined according to Ellman’s method and Bowler’s and Tirri’s, respectively. Results: After a 1-3 h CDP-choline preincubation, this substance induced a maximal stimulation of 20%-25% (p &lt; 0.001) for AChE and 50-55% (p &lt; 0.001) for Na+,K+-ATPase, but it did not influence Mg2+-ATPase activity. One mM acetylcholine (ACh) resulted in an approximately 18% (p &lt; 0.001) AChE inhibition by excess substrate in the brain homogenate, while 0.01 mM noradrenaline did not influence Na+,K+-ATPase activity. Conclusions: CDP-choline can stimulate brain AChE and Naf,K+ ATPase independently of ACh and noradrenaline. This enzymatic stimulation may be due to the transformation of GDP-choline to membrane phophatidylcholine. The above data could explain in part the clinical effects of this substance in some neuronal disturbances. Copyright (C) 2000 The Canadian Society of Clinical Chemists

l-Cysteine and glutathione restore the modulation of rat frontal cortex Na+, K+-ATPase activity induced by aspartame metabolites

Background: Studies have suggested that aspartame (ASP) ingestion is implicated in neurological problems. Aim: The aim of this study was to evaluate rat frontal cortex Na+, K+-ATPase and Mg2+-ATPase activities after incubation with ASP or each of its metabolites, phenylalanine (Phe), methanol (MeOH) and aspartic acid (asp) separately. Method: Suckling rat frontal cortex homogenates or pure Na+, K+-ATPase were incubated with ASP metabolites. Na+, K+-ATPase and Mg2+-ATPase activities were measured spectrophotometrically. Results: Incubation of frontal cortex homogenate or pure Na+, K+-ATPase with various ASP concentrations as expected in the cerebrospinal fluid (CSF) after ASP consumption of 34, 150 or 200 mg/kg, decreased the frontal cortex enzyme activity by 33%, 53% or 57%, respectively, whereas pure enzyme was remarkably stimulated. Moreover, incubation of frontal cortex homogenate with each one of the expected ASP metabolites in the CSF, except MeOH, which are related to the intake of the above mentioned doses of the sweetener, resulted in an activation of the membrane Na+, K+-ATPase, as well as pure enzyme. Frontal cortex Mg2+-ATPase remained unaltered. Addition of l-cysteine (cys) or reduced glutathione (GSH) to ASP metabolites mixtures, corresponding to 150 or 200 mg/kg doses of the sweetener, completely or partially restored to normal the modulated membrane and pure Na+, K+-ATPase activities. Conclusion: CSF concentrations of the sum of ASP metabolites corresponding to the intake of common, abuse or toxic doses (34 or 150 or 200 mg/kg, respectively) of the additive significantly increased rat frontal cortex Na+, K+-ATPase and pure enzyme activities. Cys or GSH completely or partially restored to normal both enzyme activities, possibly due to amelioration of the cellular GSH reduction from the action of MeOH, a metabolite of the sweetener and/or by their scavenging effect. © 2008 Elsevier Ltd. All rights reserved

Protective effect of L-phenylalanine on rat brain acetylcholinesterase inhibition induced by free radicals

Objective: To investigate whether the preincubation of brain homogenates with L-phenylalanine (Phe) could reverse the free radical effects on brain acetylcholinesterase (AChE) activity, since it has been reported that Phe binds hydroxyl radicals ((OH)-O-.). Design and methods: Two well established systems were used for production of free radicals: (a) FeSO4 (84 mu M) plus ascorbic acid (400 mu M), and (b) FeSO4, ascorbic acid and H2O2 (1 mM) at 37 degrees C in homogenates of adult rat whole brain. Changes in brain AChE activity were studied in the presence of each system separately. Results: AChE was inhibited (18-28%) by both systems of free radicals. This inhibition was reversed when the brain homogenate was preincubated with Phe 1.8 mM. Conclusions: In accordance with our previous reports, Phe could protect against the direct action of (OH)-O-. radicals on brain AChE and in this way it might be useful in the prevention of certain cholinergic neural dysfunctions. Copyright (C) 2000 The Canadian Society of Clinical Chemists

Effect of L-carnitine administration on the modulated rat brain protein concentration, acetylcholinesterase, Na+K+-ATPase and Mg2+-ATPase activities induced by forced swimming

Background: Forced exercise produces free radicals and L-carnitine (L-C) administration reduces oxidative stress. Aim: To investigate whether short (2 hours) or prolonged (3 hours) forced swimming could modulate total anti-oxidant status (TAS), protein concentration and activities of acetylcholinesterase (AChE), Na+K+-ATPase and Mg2+-ATPase in rat brain following intraperitonal administration of L-C (300 mg/kg). Methods: TAS, protein and enzyme activities were measured spectrophotomethcally. Results: TAS, protein concentration and AChE activity were reduced, whereas Na +K+-ATPase and Mg2+-ATPase were significantly increased after either 2 or 3 hours of training. L-C administration resulted in a profound restoration of TAS and protein concentration whereas AChE and Na +K+-ATPaSe were increased before exercise, followed by AChE restoration and Na+K+-ATPase reduction after exercise. Mg2+-ATPase remained unchanged. An in vitro study using L-C incubation of brain homogenates previously treated with L-C resulted in complete restoration of the modulated enzymes, whereas the enzyme activities from untreated animals remained unaltered. Conclusions: Short or prolonged swimming in rats may result in a reduction of brain TAS, protein concentration and AChE activity, and an activation of Na+K+-ATPaSe and Mg2+-ATPase. L-C administration may prevent reduction in TAS and protein concentration, and a decrease in AChE and Na+K +-ATPase activity; the latter reached preexercise values after L-C incubation