Free Amino Acids In Brain Research Articles

Osmoregulatory role of amino acids in brain of the elasmobranch, Raja erinacea

1. 1. Following gradual acclimation of skates ( Raja erinacea) to 50% seawater, amino acid content of brain measured as ninhydrin-positive substances decreased 52%, while plasma osmolarity fell 35%. 2. 2. Taurine constituted 50% of the total free amino acids in brain. 3. 3. During sudden transfer to 50% seawater NPS in brain fell 25% within 4 hr, then after a more gradual decrease levels stabilized at 72 hr (52% decrease). 4. 4. In vitro experiments using ouabain and LiCl suggest that the osmoregulatory efflux of amino acids may be associated with lowered Na + concentrations in extracellular fluid thereby affecting Na +- K +-dependent ATPase activity.

Free Amino Acids in Brain, Liver, and Skeletal Muscle Tissue of Voles Infected with Trypanosoma brucei gambiense

The concentrations of several acidic and neutral amino acids of brain, liver, and skeletal muscle were determined in field voles, Microtus montanus, and compared to values obtained from voles harboring a chronic infection of Trypanosoma brucei gambiense. All of the amino acids examined were found at comparable levels in brain tissue from both groups of animals with the exception of tyrosine, which was reduced by approximately 45% in the infected voles. Similarly, the only difference noted in liver tissue was 32% decrease of free tyrosine in the infected animals. With respect to muscle tissue, in addition to a 45% reduction of free tyrosine in the infected voles, decreases of a smaller magnitude were also noted for threonine, glutamate, and valine. The relatively specific alteration of free tyrosine concentrations in the investigated tissues of trypanosome-infected animals suggests an alteration in host metabolism of this amino acid and/or parasite utilization.

Experimental protein and energy deficiencies: effects on brain free amino acid composition in rats

1. The effects of protein-energy malnutrition on brain free amino acids of acidic and neutral groups were investigated in experimental rats. 2. Severe energy restriction did not modify the free amino acid composition of the brain while protein deficiency affected certain amino acids of the brain in opposite directions. Significant decreases in the levels of aspartic acid, threonine and tyrosine were observed in the protein-deficient rats. 3. These changes in brain amino acids appear to be specific to protein deficiency and not affected by energy deficiency.

Strain differences in the response to morphine on incorporation of 3H-lysine into rat brain protein.

The effect of morphine on the specific activity (SA) of lysine in the plasma free amino acid (FAA) fraction and in the cerebral cortical FAA and protein fractions, as well as on the specific accumulation and incorporation, was determined in male Sprague-Dawley and Wistar rats at various time intervals after intravenous injection of drug and amino acid into unanesthetized animals. The lysine SA was higher in Sprague-Dawley than in Wistar rats in the plasma and brain FAA fraction and in the protein fraction. In the SD strain, morphine decreased the SA of plasma FAA significantly, but had only slight effects in the Wistar strain. In the cortical gray matter, morphine elevated the SA of lysine significantly in both strains, although the rate of decrease of SA with increasing time after injection was different in the two strains. SA of the lysine in cerebral cortical protein increased in both strains with time, but did so more rapidly in the Sprague-Dawley strain. When the data for the free amino acids were expressed in terms of specific accumulation, the observed rates were higher in the Sprague-Dawley animals and reached a point of maximal concentration, which was not observed in animals of the Wistar strain. Morphine elevated the levels of specific accumulation of lysine into the cortical free amino acid pool in both strains of rat. However, specific incorporation of lysine into the cerebral gray cortical protein in control animlas was essentially similar in both strains. Despite the similarity in specific incorporation of lysine into brain protein in both strains of control rat, morphine treatment caused a much more marked inhibition of incorporation of lysine in the Wistar rats. Thus, it is concluded that Sprague-Dawley and Wistar rats are not equivalent in relation to the accumulation of an amino acid in the brain FAA pool from the plasma and that the effect of morphine on specific incorporation of lysine into brain protein is greater in Wistar rats.

BIOCHEMTCAL CHANGES IN THE BRAIN OF EXPERIMENTAL ANIMALS IN RESPONSE TO ELEVATED PLASMA HOMOCYSTINE AND METHIONINE

AbstractThe effects of high plasma concentrations of homocystine and methionine on the free amino acids of brain have been examined. Incorporation of the label from [35S]methionine into the free amino acid pools of rabbit brain was enhanced in response to high plasma homocystine or high plasma homocystine and mcthionine. Under comparable conditions a marked decrease in the incorporation of the label from [14C]glycine into the free pool was observed. The corresponding incorporation of 35S and 14C into brain proteins parallelled the results obtained with incorporation into the free pools of amino acids. Amino acid analyses of the free amino acid pools of rabbit brain revealed a general decrease in the concentration of amino acids in response to high plasma homocystine or high plasma homocystine and methionine. Inhibition of protein synthesis which occurs under the above experimental conditions is a general phenomenon. myelin and other brain fractions being equally affected. The decrease in concentration of brain amino acids also results in a diminution in concentration of the neurotransmitters GABA, dopamine and noradrenaline. The possible relationship of the observed changes to homocystinuria is discussed.

Postnatal changes in free amino acid, DNA, RNA and protein concentrations of miniature swine brain.

Abstract—Postnatal developmental characteristics of miniature swine brain were evaluated through the first 9 weeks of age. Differential growth rates of cerebrum, cerebellum and brain stem were defined in terms of DNA, RNA, protein and free amino acid concentrations at ages 5, 21, 35 and 63 days. Within the experimental conditions provided, hyperplasia ceased just prior to ages 21, 35 and 63 days for cerebellum, brain stem and cerebrum, respectively. An additional cerebral growth spurt, observed between weaning at age 35 days and sacrifice at age 63 days, may be indicative of impaired brain development due to inadequate nutrition provided by the dam's milk. Developmental changes in mean concentrations of brain free amino acids varied with anatomical area and differed somewhat from those of other species previously reported. For example, mean cerebral concentrations of aspartic acid, γ‐aminobutyric acid and asparagine + glutamine decreased significantly (P < 0·05) with age and mean glutamic acid concentration was 5 times that of taurine.

Biogenic amines and body temperature in the hen Gallus domesticus.

ARTICLESBiogenic amines and body temperature in the hen Gallus domesticusNR Scott, and A van TienhovenNR Scott, and A van TienhovenPublished Online:01 Dec 1974https://doi.org/10.1152/ajplegacy.1974.227.6.1399MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByOral Administration of L-Citrulline Changes Brain Free Amino Acid and Monoamine Metabolism in Heat-Exposed Broiler Chickens5 April 2022 | Frontiers in Animal Science, Vol. 3A landmark contribution to poultry science—A possible mode of action of sulfamethazine on the reproductive system of Leghorn cockerelsPoultry Science, Vol. 88, No. 4Temperature RegulationThermal characterization and transmitter analysis of single units in the preoptic and anterior hypothalamus of conscious ducksPfl�gers Archiv European Journal of Physiology, Vol. 411, No. 1Behavioral effects of intraventricular dibutyryl cyclic AMP in domestic fowlPhysiology & Behavior, Vol. 37, No. 3Dopamine and thermoregulation: An evaluation with special reference to dopaminergic pathwaysNeuroscience & Biobehavioral Reviews, Vol. 9, No. 4Evidence for a positive feedback interaction between progesterone and luteinizing hormone in the induction of ovulation in the hen, Gallus domesticusGeneral and Comparative Endocrinology, Vol. 58, No. 3Feeding, drinking and body temperature of leghorn chicks: Effects of ICV injections of biogenic aminesPhysiology & Behavior, Vol. 31, No. 1Food Intake and Temperature Response to Injections of Catecholamines into the Lateral Ventricle of the Turkey BrainPoultry Science, Vol. 62, No. 6Role of the Dopaminergic System in Luteinizing Hormone Release and Ovulation in the HenPoultry Science, Vol. 60, No. 11Eating, drinking and temperature response of chicks to brain catecholamine injectionsPhysiology & Behavior, Vol. 27, No. 2Plasma concentrations of corticosterone relative to photoperiod, oviposition, and ovulation in the domestic henGeneral and Comparative Endocrinology, Vol. 43, No. 1Hypothermic effect of dopamine and l-dopa in the domestic fowl (Gallus Domesticus)General Pharmacology: The Vascular System, Vol. 12, No. 5HYPOTHALAMO-HYPOPHYSEAL SENSITIVITY TO CENTRAL INJECTIONS OF PROGESTERONE AND LH-RH IN THE LAYING AND MOLTING HENChanges in body temperature after administration of adrenergic and serotonergic agents and related drugs including antidepressantsNeuroscience & Biobehavioral Reviews, Vol. 4, No. 3Changes in body temperature after administration of amino acids, peptides, dopamine, neuroleptics and related agentsNeuroscience & Biobehavioral Reviews, Vol. 3, No. 4The Hypothalamus and Thermoregulation: A ReviewPoultry Science, Vol. 58, No. 6Dopaminergic mechanisms and stereotyped behaviour in birdsPharmacological Research Communications, Vol. 11, No. 7The influence of high ambient temperature on thermoregulatory response to intrahypothalamic injections of noradrenaline and serotonin in the pigeonPfl�gers Archiv European Journal of Physiology, Vol. 377, No. 1Thermoregulatory changes induced by intrahypothalamic injections of cholinomimetic substances in the pigeonNeuropharmacology, Vol. 16, No. 11Thermoregulatory effects of intraventricularly injected dopamine in the goatEuropean Journal of Pharmacology, Vol. 43, No. 1 More from this issue > Volume 227Issue 6December 1974Pages 1399-1405 Copyright & PermissionsCopyright © 1974 by American Physiological Societyhttps://doi.org/10.1152/ajplegacy.1974.227.6.1399PubMed4440784History Published online 1 December 1974 Published in print 1 December 1974 Metrics

2588. Mechanism of carbon disulphide neurotoxicity: Tarkowski, S. & Cremer, Jill E. (1972). Metabolism of glucose and free amino acids in brain, studied with 14C-labelled glucose and butyrate in rats intoxicated with carbon disulphide. J. Neurochem.19, 2631

2588. Mechanism of carbon disulphide neurotoxicity: Tarkowski, S. & Cremer, Jill E. (1972). Metabolism of glucose and free amino acids in brain, studied with 14C-labelled glucose and butyrate in rats intoxicated with carbon disulphide. J. Neurochem.19, 2631

Rat brain and blood gluconeogenic metabolic changes in neonatal starvation

Summary Newborn rats fasted for 24 h immediately after birth lost about 80% of their brain free alanine and 50% of glutamate plus glutamine per cell unit as compared with their fed littermates. These changes occurred simultaneously with a pronounced decline in the same circulating amino acids. Exhaustion of these brain free gluconeogenic amino acids paralleled a marked hypoglycemia (glucose

The effect of chronic meprobamate treatment on brain free amino acid levels of rats

Summary Brain free amino acid levels have been estimated in rats following prolonged meprobamate administration and during recovery from the drug. Increases and decreases of the brain free amino acid levels have been observed. There was some return to control levels during recovery. The role of free amino acids in physical dependence on and abstinence to meprobamate is discussed.

2588. Mechanism of carbon disulphide neurotoxicity: Tarkowski, S. & Cremer, Jill E. (1972). Metabolism of glucose and free amino acids in brain, studied with 14C-labelled glucose and butyrate in rats intoxicated with carbon disulphide. J. Neurochem.19, 2631

2588. Mechanism of carbon disulphide neurotoxicity: Tarkowski, S. & Cremer, Jill E. (1972). Metabolism of glucose and free amino acids in brain, studied with 14C-labelled glucose and butyrate in rats intoxicated with carbon disulphide. J. Neurochem.19, 2631

Metabolism of glucose and free amino acids in brain, studies with 14C-labelled glucose and butyrate in rats intoxicated with carbon disulphide.

Abstract— The effect of 15 h continuous exposure to CS2 on the metaboliam of glucose and free amino acids in the brain of rats was studied. CS2 caused a moderate hypoglycaemia. There were also changes in the amounts of some amino acids in the brain. Glutamate and γ‐aminobutyrate were lower whereas glutamine was markedly increased. Comparative studies in vivo of the metabolism of [2‐14C]glucose and [1‐14C]butyrate indicated that CS2 did not affect glycolysis or the incorporation of 14C from glucose into amino acids except into γ‐aminobutyrate which was reduced. Contrary to the findings with [14C]glucose, CS2 provoked distinct changes in the labelling of amino acids when [14C]butyrate was the precursor. The most notable change was a markedly increased incorporation of 14C into glutamine. Based on the two‐compartment model of brain glutamate the experimental findings indicated that CS2 affected metabolism associated with the ‘small’ pool of glutamate but had a minimal effect on metabolism associated with the ‘large’ glutamate pool. The possibility is suggested that the changes observed involved an increased rate of ammonia removal. The low incorporation of 14C into γ‐aminobutyrate from either precursor is consistent with other evidence showing that CS2 interferes with pyridoxal phosphate‐dependent enzymes.

Incorporation of carbon atoms from glucose into free amino acids in brain under normal and altered conditions.

The time course of entry of radioactive carbon from intravenously administered [U-14C]-glucose into free amino acids in the brains of rats has been studied using an automatic amino acid analyzer coupled through a flow cell with a scintillation counter. Radioactivity appeared rapidly in alanine, aspartic acid, glutamic acid, glutamine, and γ-aminobutyric acid as previously shown, and in an unknown ninhydrin-positive substance present in very small amount. Urea, serine, and glycine became slightly radioactive. Four hours after giving the radioactive glucose, the specific activity in all soluble substances was low. In pentobarbital anesthesia, specific radioactivity was increased in alanine and decreased in γ-aminobutyric acid, aspartic and glutamic acids, and glutamine. A high proportion of radioactivity remained in glucose. Under hypoxia, alanine increased in amount but decreased in specific activity, and the specific activities of the other strongly labelled amino acids decreased. The proportion of the total radioactivity found in glucose and lactate increased. During picrotoxin and pentylenetetrazol convulsions, changes occurred which were similar to those under hypoxia. After aminooxyacetic acid administration, the well-known great increase in γ-aminobutyric acid level was found to be accompanied by a decrease in glutamate and also in aspartic acid and alanine, indicating inhibition of the three transaminases concerned. The previously observed brief rapid postmortem increase in the amount of γ-aminobutyric acid was confirmed; alanine also increased briefly but no other amino acid did so. The increased γ-aminobutyric acid had the same specific radioactivity as the original but the extra alanine was less radioactive than the original. When the γ-aminobutyric acid level had been increased by administration of aminooxyacetic acid, the rapid postmortem increase did not occur.

Decarboxylation studies of glutamate, glutamine, and aspartate from brain labelled with [1-14C]acetate, L-[U-14C]-aspartate, and L-[U-14C]glutamate.

Abstract—Studies in vivo and in vitro of the distribution of label in C‐1 of glutamate and glutamine and C‐4 of aspartate in the free amino acids of brain were carried out. [1‐14C]‐Acetate was used both in vivo and in vitro and l‐[U‐14C]aspartate and l‐[U‐14C]glutamate were used in vitro. The results obtained with labelled acetate and aspartate suggest that CO2 and a 3‐carbon acid may exchange at different rates on a COa‐fixing enzyme. The apparent cycling times of both glutamate and glutamine show fast components measured in minutes and slow components measured in hours. With [1‐14C]acetate in vitro glutamine is more rapidly labelled in C‐1 than is glutamate at early time points; the curves cross over at about 7 min. The results support and extend the concept of metabolic compartmentation of amino acid metabolism in brain.

The free amino acids of brain and liver during fetal life of Macaca mulatta.

The relative concentrations of all free amino acids which can be part of protein molecules of animal tissue probably influence the rate of protein synthesis at the cellular level. The other ninhydrin positive compounds in the cell detected during free amino acid analysis should indicate the metabolic activity of these low-molecular weight compounds.In this report the free amino acid levels in the brain and the liver of fetal monkeys at different stages of gestation and shortly after birth are given. These data are part of a study of fetal development in a subhuman primate, whose placenta is structurally comparable to the human placenta. Other parts of this developmental study referring to free amino acids in the serum during pregnancy and fetal life of the M. mulatta have been reported by Kerr (1).Although several studies can be found in the literature on free brain amino acids in young animals, fragmentary data on only a small number of fetal brains are available, and then mostly as part of another study...

Effect of serotonin on the level of free amino acids in brain and liver tissue

Effect of serotonin on the level of free amino acids in brain and liver tissue

Utilization in vivo of glucose and volatile fatty acids by sheep brain for the synthesis of acidic amino acids

1. Free glutamic acid, aspartic acid, glutamic acid from glutamine and, in some instances, the glutamic acid from glutathione and the aspartic acid from N-acetyl-aspartic acid were isolated from the brains of sheep and assayed for radioactivity after intravenous injection of [2-(14)C]glucose, [1-(14)C]acetate, [1-(14)C]butyrate or [2-(14)C]propionate. These brain components were also isolated and analysed from rats that had been given [2-(14)C]propionate. The results indicate that, as in rat brain, glucose is by far the best precursor of the free amino acids of sheep brain. 2. Degradation of the glutamate of brain yielded labelling patterns consistent with the proposal that the major route of pyruvate metabolism in brain is via acetyl-CoA, and that the short-chain fatty acids enter the brain without prior metabolism by other tissue and are metabolized in brain via the tricarboxylic acid cycle. 3. When labelled glucose was used as a precursor, glutamate always had a higher specific activity than glutamine; when labelled fatty acids were used, the reverse was true. These findings add support and complexity to the concept of the metabolic ;compartmentation' of the free amino acids of brain. 4. The results from experiments with labelled propionate strongly suggest that brain metabolizes propionate via succinate and that this metabolic route may be a limited but important source of dicarboxylic acids in the brain.

Effects in vivo and in vitro of l-glutamic acid-γ-hydrazide on metabolism of some free amino acids in brain and liver

Further research on the effect of l-glutamic acid-γ-hydrazide (GAH) on free amino acids metabolism in brain is reported. Similar studies of free amino acid metabolism in liver are also presented. The addition of GAH to mice brain homogenates inhibited the activities of γ-aminobutyrate aminotransferase (ABAT), and of glutamate decarboxylase (GAD). The activities of alanine aminotransferase (AAA) and of aspartate aminotransferase (ASA) were not affected by GAH in these conditions. Brain homogenates from GAH-treated mice showed lower GAD, ABAT, AAA, and β-alanine-α-ketoglutaric aminotransferase (βAA) activities than brain homogenates from control mice. GAD activity was inhibited by GAH to a considerably lesser extent in vivo than in vitro. In liver, GAH produced a striking increase in the concentrations of almost all the free amino acids, especially of alanine and β-alanine. The addition of GAH to mice liver homogenates inhibited the βAA activity, but neither AAA nor ASA activity was affected by the same concentration of GAH. Liver homogenates from GAH-treated mice showed diminished βAA and AAA activity in comparison with liver homogenates from control mice. Some differences in the conversion of uniformly labeled 14C- glucose to liver and brain free amino acids were found between control and GAH-treated mice. In the brain of the latter animals, aspartic and glutamic acids and glutamine exhibited initially a higher specific activity than in control mice. In the case of γ-aminobutyric acid and alanine, opposite results were obtained. In the GAH-treated animals these two amino acids showed no significant decay of the acquired radioactivity. In liver, the decay of the acquired radioactivity of alanine tended to be slower in GAH-treated animals than in control animals.

The effect of psychotropic drugs on the utilization of glucose carbon atoms in the brain, heart and liver of the rat

Measurements were made of (a) the concentration of free amino acids, (b) the content of 14C in the total acid-soluble fraction and (c) the incorporation of 14C into amino acids of the rat brain, heart, liver and blood at 20 min after injection of [U- 14C]glucose. The effect of reserpine, iproniazid, chlorpromazine, pentobarbitone (sodium), ethylether, ethanol, electroshock and restraint by binding were examined. Reserpine inhibited markedly the uptake of 14C from [ 14C]glucose in the heart. Pentobarbitone (sodium) inhibited the incorporation of 14C into the free amino acids in brain and liver. Reserpine and ethanol inhibited the incorporation of 14C into amino acids in the liver, but not in the brain.

Free amino acids in brain of mice treated with l-glutamic acid-γ-hydrazide

Glutamate decar☐ylase (GAD) activity and [14C]leucine incorporation into brain protein in vivo were measured in mice injected withl-glutamic acid -γ-hydrazide and 60 min later with pyridoxal-5′-phosphate; this combined treatment produces a decrease in GAD activity and an increase in GABA levels. Under such conditions, protein synthesis was inhibited to the same extent as GAD activity.A parallelism between the decrease in GAD activity and that in protein synthesis was also observed in brain cortex slices treated with GAD inhibitors. This treatment did not affect leucine incorporation into protein in liver slices. The results support the previously suggested hypothesis that a certain pool of GABA may have a role in the regulation of protein synthesis in brain, and further suggest that the synthesis of GABA may be more important in this respect than its total concentration.