bluuebunny/crossref_metadata_2025 huggingface dataset:
THE REGIONAL DISTRIBUTION OF d‐GLYCERATE DEHYDROGENASE AND 3‐PHOSPHOGLYCERATE DEHYDROGENASE IN THE CAT CENTRAL NERVOUS SYSTEM: CORRELATION WITH GLYCINE LEVELS
Authors: Uhr M. L. , Sneddon M. K.
Published: October 2006

The activities of d‐glycerate dehydrogenase, 3‐phosphoglycerate dehydrogenase and lactate dehydrogenase have been measured in high‐speed supernatant fractions from different regions of the cat CNS. Only d‐glycerate dehydrogenase showed any significant regional variation in levels of activity, and this regional distribution correlated well with the regional distribution of glycine. In view of the previous finding that glycine inhibits d‐glycerate dehydrogenase of rat cortex in a non‐competitive manner suggesting endproduct inhibition (Uhr and Sneddon, 1971) this correlation is considered additional evidence to suggest that d‐glycerate may be an important source of glycine in the CNS.
THE APPARENT TURNOVER OF MITOCHONDRIA, RIBO‐SOMES AND sRNA OF THE BRAIN IN YOUNG ADULT AND AGED RATS1
Authors: Menzies R. A. , Gold P. H.
Published: October 2006

—[14C] orotic acid and [3H]l‐leucine were injected intraperitoneally into two groups of rats, aged 12 and 24 months, respectively. The apparent turnover of RNA and protein from several subcellular fractions was assessed by following the loss of label from these fractions with time. The curves for apparent turnover of all protein fractions from mitochondria were single exponential curves. Total mitochondrial protein from younger animals had a half‐life of 26.8 days. Two protein subfractions, protein insoluble in cold perchloric acid and chloroform‐methanol (residual protein) and protein soluble in chloroform‐methanol (C–M protein) had similar half‐lives: 26.3 and 26.1 days, respectively. For the older animals the half‐lives were 23.5 days for total protein, 17.4 for residual protein and 30.4 for C–M protein. The difference between the two protein subfractions from mitochondria of the older animals suggests an age‐associated deviation from the synchrony of synthesis and degration of proteins in this organelle.

Further deviation from the unit concept of mitochondrial turnover was seen in the apparent turnover of mitochondrial RNA. Mitochondrial RNA had half‐lives of 10.0 and 11.6 days for older and younger animals, respectively, with no significant difference between the groups. No age‐associated difference was observed in the apparent turnover of sRNA. This fraction exhibited a double exponential turnover pattern; the first component in both cases had a half‐life of about 5–8 days and the second component 13–16 days. Ribosomal RNA and protein from both older and younger animals exhibited multiexponential kinetics but both components, RNA and protein, within each age group appeared to turn over synchronously. Average values for apparent turnover of total ribosomes (RNA and protein) were 18.2 days for the older animals and 7.4 days for the younger animals. The age‐associated difference was highly significant P < (0.001).
ACCUMULATION OF GLUTAMIC ACID IN THE ARCUATE NUCLEUS OF THE HYPOTHALAMUS OF THE INFANT MOUSE FOLLOWING SUBCUTANEOUS ADMINISTRATION OF MONOSODIUM GLUTAMATE1
Authors: Perez V. J. , Olney J. W.
Published: October 2006

—Monosodium l‐glutamate was injected subcutaneously into 4‐day‐old mice at a dose of 2 mg/g body wt. The infants were killed at sequential intervals after injection, the brains were frozen, and samples of the arcuate nucleus (NA), ventromedial hypothalamus (VMH) and lateral thalamus (LT) were micro‐dissected from lyophilized sections for glutamate assay. Blood glutamate levels were also determined for comparison with brain levels of glutamate at corresponding post‐injection intervals. Glutamate levels in the NA steadily increased to reach a peak value of 110.9 mmol/kg dry wt. at 3 h following injection, whereas the highest levels reached in the VMH or LT were about 41.7 mmol/kg dry wt. Return to control values of about 25 mmol/kg dry wt. occurred gradually over a period of 12–15 h in all three brain regions. Blood glutamate concentrations peaked rapidly, reaching a maximum of 40 mm within 15 min but returned precipitously to near‐baseline values (below 1 mm) in the 1–3 h interval after injection. We discuss possible mechanisms to account for the transient marked accumulation of subcutaneously administered glutamate in the NA and how this might relate to the selective destruction of arcuate neurons which occurs simultaneously.
ENZYMIC ACTIVITIES IN DISSOCIATED NEURONS DIFFERENTIATED IN CULTURES IN VITRO
Authors: Contestabile A. , Minelli G. , Ciani F.
Published: October 2006

Abstract— The appearance of the enzymes succinate dehydrogenase, lactate dehydrogenase, acid phosphatase, monoamine oxidase and acetylcholinesterase in cultures of dissociated spinal cord, dorsal root ganglia and cerebellum removed at different stages of development have been studied. The neurons differentiated in vitro have morphological and cytochemical characteristics similar to those of the normally developing neurons. On the basis of the results obtained, it is argued that in this experimental model the histogenetic determination of the neuroblasts at the time of the explant may start and bring to an end the morphological and biochemical differentiation of the various types of neurons even under conditions extremely different from those of normal development.
FORMATION OF PUTREANINE, N‐(4‐AMINOBUTYL)‐3‐AMINOPROPIONIC ACID FROM SPERMIDINE IN RAT BRAIN AND LIVER
Authors: Nakajima T.
Published: October 2006

Abstract— Putreanine was proven to be formed from spermidine in rat brain by intra‐ventricular injection of radioactive spermidine. The ability to form putreanine from spermidine was also found in rat liver. The turnover rate of putreanine was slower in rat brain than in rat liver.
THE DISTRIBUTION AND PROPERTIES OF THE NONSPECIFIC N‐METHYLTRANSFERASE IN BRAIN
Authors: Saavedra J. M. , Coyle J. T. , Axelrod J.
Published: October 2006

Abstract— The distribution and properties of a nonspecific N‐methyltransferase in the rat brain are described. The enzyme N‐methylates tryptamine and N‐methyltryptamine as well as β‐phenylethylamine, phenylethanolamine, tyramine and octopamine. The enzyme exhibits a pH optimum of 7·9 with phosphate buffer and has a Km for tryptamine of 28 μM. There are potent inhibitors to the enzyme that can be removed by dialysis. Enzymatic activity is present in the brains of a number of species including man, rat, mouse, guinea‐pig and frog. Its activity is unevenly distributed in the brain with the highest activity in the cerebral cortex and striaturn of the rat and in the subcortical white matter in man. Studies of its subcellular distribution indicate that most of the N‐methylation activity is released into the soluble fraction. Enzymatic activity is also present in a number of peripheral tissues of the rat.
Enzymatic desulphation of cerebroside‐3‐sulphate by chicken brain arylsulphatase A
Authors: Farooqui A. A. , Bachhawat B. K.
Published: October 2006

In Earlier work from this laboratory it was shown that arylsulphatase of chicken brain resembles arylsulphatase A of other animal species in several of its properties but exhibits certain characteristics similar to that of arylsulphatase B (Farooqui and Bachhawat, 1971). Recently the arylsulphatase A of chicken brain was purified and it was demonstrated that the purified enzyme could desulphate cerebroside‐3‐sulphate also (Farooqui and Bachhawat, 1972). In the present report we have made a study of the kinetic properties of this unique arylsulphatase A purified from chicken brain using p‐nitrocatechol sulphate and cerebroside‐3‐sulphate as substrates.
BIOSYNTHESIS OF PSYCHOSINE AND LEVELS OF CEREBROSIDES IN THE CENTRAL AND PERIPHERAL NERVOUS SYSTEMS OF QUAKING MICE
Authors: Friedrich V. L. , Hauser G.
Published: October 2006

Abstract— The levels of cerebrosides in neural tissues of adult mice were determined by densitometry of cerebroside spots on charred thin‐layer chromatograms of washed total lipid extracts. Values for brain, spinal cord and peripheral nerves were 9·2, 33·0 and 36·9 mg/g of tissue, respectively. In adult Quaking mice these values were 6·4, 24 and 35 % of normal, respectively. Normal levels in brain, spinal cord and peripheral nerve of 21‐day‐old mice were 3·10, 13·5 and 17·8 mg/g, respectively. In 21‐day‐old Quaking mice the levels were reduced to 16,21 and 57% of normal, respectively. Biosynthesis of psychosine (galacto‐sylsphingosine) by homogenates of Quaking brain, spinal cord and peripheral nerve, respectively, was 18, 24 and 42% of the normal rates at 21 days after birth and 16, 66 and 60% of the normal rates at 94 days. Our results suggest a quantitative relationship between the rate of formation of psychosine in vitro and the rate of accumulation of cerebrosides. in vivo. Biosynthesis of lactosylceramide was not reduced in homogenates of brain and spinal cord from Quaking mice. Cerebroside levels in normal and Quaking spinal cord and in normal brain increased 2‐ to 3‐fold after 21 days of age, but in Quaking brain there was little or no increase.
AMINO‐ AND CARBOXYL‐TERMINAL AMINO ACIDS OF PROTEOLIPID PROTEINS1
Authors: Whikehart D. R. , Lees Marjorie B.
Published: October 2006

The amino‐ and carboxyl‐terminal amino acids of proteolipids from neural and non‐neural sources were investigated. Amino‐terminal amino acids were identified and quantitated by the dansyiation procedure. Carboxyl‐terminal amino acids were determined after hydrazinolysis or enzymatic hydrolysis with carboxypeptidases. Proteolipid from white matter showed two terminal amino acids, regardless of the method of preparation. The major N‐terminal amino acid was glycine and the minor one was glutamic acid or glutamine. The corresponding C‐terminal amino acids were phenylalanine and glycine. Preparations of white matter proteolipid, therefore, contained more than one protein or protein chain. Proteolipids from brain mitochondria, heart, liver and kidney were characterized by N‐terminal aspartic acid or asparagine and C‐terminal lysine residues and they exhibited an amino acid composition which differed from white matter proteolipid. Our results suggest the existence of two classes of proteolipids, a myelin type and a non‐myelin type. Synaptic membrane and grey matter proteolipids exhibited characteristics of both classes.
AN IMPROVED SULPHUR ASSAY APPLIED TO A PROBLEM OF ISETHIONATE METABOLISM IN SQUID AXON AND OTHER NERVES1
Authors: Hoskin F. C. G. , Brande M.
Published: October 2006

An assay has ken developed for total sulphur which is based on a wet oxidation and measurement with a spectrophotofluorometer of light scattering by barium sulphate. The method has been adapted to the measurement of isethionate in squid nerve and blood, in other cephalopod nerve, and in the nerve tissue of other species including mammals. A correlation has been found between isethionate contents and the activity in the same tissues of one kind of DFP‐hydrolysing enzyme, the highest levels of both being in squid nerve. Squid nerve also took up cysteine rapidly and metabolized it predominantly to hypotaurine but not to isethionate. We speculate that a hypotaurine derivative is a reserve form of isethionate, and that the so‐called DFPase is involved in the release of hypotaurine and its metabolism to isethionate as needed.
INCORPORATION OF 14C FROM [U‐14C]GLUCOSE INTO FREE AMINO ACIDS IN MOUSE BRAIN LOCI IN VIVO UNDER NORMAL CONDITIONS
Authors: Shimada M. , Kihara T. , Kurimoto K. , Watanabe M.
Published: October 2006

By macroautoradiography and by GLC separation, differences in the uptake of radioactive carbon from [U‐14C]glucose into free amino acids (glutamate + glutamine, aspartate + asparagine, GABA, alanine and glycine) in mouse cerebral neocortex, hippocampus, thalamus and hypothalamus were investigated.

(1) The autoradiographical densities in the thalamus, cerebral neocortex and hippocampus measured with a microdensitometer were higher than that in the hypothalamus at 5 min after subcutaneous injection. At 180 min, densities in the cerebral neocortex, hippocampus and hypothalamus were higher than that in thalamus.

(2) The free amino acid levels determined by GLC varied with each brain region.

(3) The specific radioactivity (d.p.m./μmol) of alanine in each brain region was higher than that of the other amino acids at 5 min after the injection. The specific radioactivity of GABA in the brain regions was clearly higher than that of (glutamate + glutamine), (aspartate + asparagine) and glycine at 5 and 15 min.

(4) The autoradiographical data were in good agreement with the chemical data at 5 min but were different at 180 min.

(5) Variations in specific radioactivity of each free amino acid among brain regions at 5 min were influenced greatly by existing free amino acid concentrations in each region.
Aromatic amino acid transaminases in rat brain
Authors: Minatogawa Y. , Noguchi T. , Kido R.
Published: October 2006

The Transamination of aromatic amino acids in brain is of interest due to its involvement in the biosynthesis of catechol and indole amines. Previous reports have established the presence of aromatic amino acid transaminases in brain (Canellakis and Cohen, 1962; Albers, Koval and Jakoby. 1962; Haavaldsen, 1962).

It was subsequently reported that rat brain extracts contain at least three aromatic amino acid transaminases (Transaminase‐I, II and III) (Fosnum, Haavaldsen and Tangen, 1964; Tangen, Fowum and Haavaldsen, 1965: Fohwum and Larsen, 1965): Transaminase‐I had a high affinity for DOPA, Transaminase‐II an affinity for phenylalanine and tyrosine, and Transaminase‐III an affinity for tryptophan and 5‐HTP. The preferred aminoacceptor of these enzymes was 2‐oxoglutarate or oxaloacetate.

The present paper describes the aromatic amino acid transaminases in an extract of rat brain, which differ from the three transaminases described by Tangenet al. (1965).
THE OCCURRENCE OF A GLYCINE CLEAVAGE SYSTEM IN MAMMALIAN BRAIN1
Authors: Bruin W. J. , Frantz B. May , Sallach H. J.
Published: October 2006

A major catabolic route for glycine in liver is its conversion to methylene tetra‐hydrofolate (methylene THF), CO2 and NH3, catalysed by the glycine cleavage system described by Yoshida and Kikuchi (1970). In view of the role of glycine as a putative neuro‐transmitter, the occurrence of this system in mammalian brain was investigated. Our studies demonstrated: (a) that the production of 14CO2 from [1‐14C]glycine required the presence of tetrahydrofolate, NAD, dithiothreitol and pyridoxal phosphate in the reaction mixture; (b) that besides CO2l‐serine was the other major product of the reaction; (c) that glyoxylate did not function as an intermediate in this reaction; and (d) that enzymatic activity appeared to be associated with membranes. All of these properties resembled those previously described for the hepatic system.
A COMPARISON OF THE NEURAL REGULATION OF TYROSINE HYDROXYLASE ACTIVITY IN SYMPATHETIc GANGLIA OF ADULT MICE AND RATS
Authors: Heendry I. A. , Iversen L. L. , Black I. B.
Published: October 2006

Surgical decentralization of the superior cervical ganglion (SCG) in rats and mice led to a fall in ganglionic tyrosine hydroxylase (T‐OH) activity, and a loss of more than 90 per cent of the preganglionic neurone marker, choline acetyl transferase. T‐OH activity was reduced by more than 50 per cent in mice SCG ten days after surgery, but fell by only 25 per cent in rat SCG after 21 days. The surgical procedure did not cause obvious histo‐logical damage or loss of SCG cells in either species. Both T‐OH and choline acetyl transferase activities in rat and mouse SCG recovered to normal three months after surgery. Reserpine treatment was more effective in rats in causing increased ganglionic T‐OH activity than in mice. Neither decentralization nor reserpine treatment caused any changes in DOPA‐decarboxylase or monoamine oxidase activities in rat SCG. These results demonstrate that T‐OH activity in SCG is subject to trans‐synaptic regulation in both rats and mice; this regulation does not apply to DOPA‐decarboxylase or monoamine oxidase. Differences in basal sympathetic tone may explain the different results obtained in mice and rats.
TYROSINE–ALPHA‐KETOGLUTARATE AMINOTRANSFERASE ACTIVITY IN RAT LIVER AFTER SPINAL CORD SECTION
Authors: Vaptzarova K. I. , Popov P. G. , Galabov G. P.
Published: October 2006

Spinal cord section brings about early and late changes in rat liver tyrosine‐alpha‐ketoglutarate aminotransferase activity. Early effects (4 h after surgery): spinal cord section at C7 level causes an unreactiveness of rat liver tyrosine‐alpha‐ketoglutarate aminotransferase both to endogenously and exogenously elevated plasma glucocorticoid levels. Induction of tyrosine–alpha‐ketoglutarate aminotransferase by hydrocortisone administration is almost completely inhibited. This unreactiveness of the rat liver enzyme to hydrocortisone is not due to delayed resorption of hydrocortisone by the peritoneum as tested with [3H]hydrocortisone, to changes in the secretion of hypophyseal hormones or to changes in the levels of glucose in blood or liver. L3 level section of the spinal cord or sham operation results in a stress‐like enzyme pattern (an increase at 4 h with return to normal level at 24 h). The stress elevation of tyrosine–alpha‐ketoglutarate aminotransferase at 4 h after the operation is absent in C7 level sectioned rats. This effect is not due to a decreased plasma corticosterone level since it is 4.1‐fold higher in C7 level sectioned rats and 2.7‐fold higher in sham‐operated controls (as measured 2.5 h after the operation).

Late effects (24 h after the surgery): C7 level section of the spinal cord brings about a nine‐fold increase in a tyrosine–alpha‐ketoglutarate aminotransferase activity in animals with intact adrenals and three‐fold increase in adrenalectomized rats at 24 h after the operation. This increase is abolished almost completely by cycloheximide, irrespective of the time of administration. Experiments with actinomycin D, injected at different times after C7 level section have shown that there exists a period of higher sensitivity of the amino‐transferase toward the antibiotic (lasting about 3 h), followed by a period of lower sensitivity (lasting 16 h or longer). These results can be explained by assuming the existence of two tyrosine‐alpha‐ketoglutarate aminotransferase mRNAs with different lifetime. A direct participation of the CNS in the changes in enzymic activity observed after section of the spinal cord above the segments innervating the liver is suggested.
ARYLSULPHATASES IN HUMAN BRAIN: PURIFICATION AND CHARACTERIZATION OF AN INSOLUBLE ARYLSULPHATASE1
Authors: Perumal A. S. , Robins E.
Published: October 2006

After solubilization with 0.5% (w/v) lysolecithin an arylsulphatase was purified 30‐fold from human brain. By this procedure, 82% of the activity was recovered in the 100,000 g supernatant fluid. Solubilization of the enyzme was dependent on lysolecithin concentration but not on the time of incubation. The enzyme was purified using ethanol and ammonium sulphate fractionations. The purified protein showed a single band on acrylamide gel electrophoresis in two different buffer systems. On ultracentrifugation, a sharp symmetrical peak was obtained with a s20,w value of 5.4 and an apparent molecular weight of 103,000 daltons was calculated. A molecular weight of 105,000 daltons was obtained by sucrose density gradient. Sodium dodecyl sulphate‐polyacrylamide gel electrophoresis showed the presence of two subunit species with molecular weights of 47,000 and 25,000 daltons. The enzyme was unstable at 04°C but could be stored in a frozen state without much loss of activity. 4‐Methylumbelliferone‐sulphate was used as substrate in these studies and the product, methylumbelliferone, was quantified fluorometrically. The enzyme had an optimum pH of 6.8. A higher activity was exhibited in imidazole buffer than in acetate buffer. Enzyme activity was linear up to 30 min of incubation. The enzyme showed a Km of 37.7 μm for 4‐methylumbelliferone‐sulphate. Ammonium sulphate at 5 mm produced a slight activation of the enzyme. Borate, silver and sulphite ions inhibited enzyme activity, whereas p‐chloromercuribenzoate, and cyanide, arsenite, fluoride and phosphate ions caused very little inhibition. The chemical enzymatic hydrolysis of the native enzyme revealed the presence of 2 mol of sialic acid per mole of the enzyme. Enzymatic removal of sialic acid did not affect the activity of the enzyme; therefore, the sialic acid moiety was not required for enzyme activity.
IMMUNOCHEMICAL AND IMMUNOFLUORESCENCE STUDIES OF BETA‐TRACE PROTEIN IN DIFFERENT SPECIES AND ORGANS, WITH SPECIAL REFERENCE TO THE CENTRAL NERVOUS SYSTEM
Authors: Olsson J.‐E. , Nord L.
Published: October 2006

—The localization of beta‐trace protein in different human organs and in the brains of other mammals has been investigated with immunochemical and immunofluorescence methods. With the double immunodiffusion technique, the immunological identity between beta‐trace protein in human CSF, brain, femoral nerve, testis, epididymis, spermatic cord, ovary and fallopian tube and in monkey brain could be demonstrated. By means of single radial immunodiffusion on agar, the highest concentrations of beta‐trace protein were found in preparations of water‐soluble proteins of brain and genital organs, especially in white CNS matter, testis and epididymis. With the indirect immunofluorescence technique, bright fluorescence was found in CNS, especially in white matter, and in the stroma of epididymis. The content of beta‐trace protein in femoral nerve was found to be considerably lower than that in the CNS. The results indicate a connexion between beta‐trace protein and the CNS, probably in the myelin or glial cells, and also between beta‐trace protein and the genital system, possibly to cells involved in steroid metabolism. A specificity for highly developed mammals, i.e. man and monkey, is proposed for beta‐trace protein, as no precipitation could be found when brain extracts from calves, rabbits or mice were incubated with anti‐serum against human beta‐trace protein.
ON THE ASSOCIATION OF NON‐SPECIFIC ESTERASE ACTIVITY WITH CENTRAL NERVE MYELIN PREPARATIONS
Authors: Rumsby M. G. , Getliffe Helen M. , Riekkinen P. J.
Published: October 2006

Abstract— Isolated bovine central nerve myelin sheath preparations showed non‐specific esterase activity towards naphthyl ester substrates of increasing chain length from acetate to palmitate. Short chain esters were hydrolysed much faster than long chain substrates by myelin, the specific activity for the hydrolysis of β‐naphthyl acetate being the highest. Micro‐somal fractions from brain white matter were much higher in esterase activity to all naphthyl ester substrates. NADPH‐cytochrome c reductase activity was absent from isolated myelin samples. Distilled water and salt and buffer solutions of different ionic strengths and pH were ineffective in releasing non‐specific esterase activity from myelin although tri‐potassium citrate caused marked inhibition of the membrane‐bound esterase activity. The detergent Triton X‐100 released esterase activity from the myelin preparations but at a concentration of 0.1 per cent was also inhibitory.
NUCLEAR PROTEINS IN BRAIN OF 7‐DAY‐OLD AND ADULT RATS
Authors: Szijan I. , Burdman J. A.
Published: October 2006

Abstract— The incorporation of radioactive leucine into proteins of rat brain was considerably higher in the 7‐day‐old than in the adult rat. The greatest difference in the rate of protein synthesis between these two stages of development occurs in the mitochondrial fraction. Among the nuclear proteins the largest variation was in the histones. The only difference in the relative content of nuclear proteins between 7‐day‐old and adult brain was in the acidic deoxyribonucleoproteins which was higher in the younger animal. The electrophoretic profile of these proteins changed during brain development.
POSTSYNAPTIC ADRENERGIC‐CYCLIC AMP CONTROL OF THE SEROTONIN CONTENT OF CULTURED RAT PINEAL GLANDS
Authors: Klein D. C. , Yuwiler A. , Weller Joan L. , Plotkin Selma
Published: October 2006

Abstract— This investigation was designed to determine whether the amount of serotonin (5‐HT) in cultured pineal glands can be altered by norepinephrine (NE). Treatment with l‐NE (10−5‐10−7m) for 4‐6 h caused a gradual decrease in the concentration of 5‐HT to a value that was less than 30% of that in the untreated control gland. This effect was observed using chronically denervated pineal glands. d‐Norepinephrine (10−6‐10−7m) and dopamine (10−4m) were ineffective in lowering 5‐HT. The effect of l‐NE was completely blocked by a β‐adrenergic receptor blocker, propranolol and was only slightly decreased by α‐adrenergic receptor blockers. These observations indicate that l‐NE acts post‐synaptically via a highly specific β‐adrenergic mechanism. The effect of l‐norepinephrine was mimicked by theophylline and N6, 2′0‐dibutyryl adenosine 3′,5′‐monophosphate, an indication that adenosine 3′,5′‐monophosphate is involved in the effect of l‐NE on 5‐HT. Treatment with cycloheximide, which by itself caused a decrease in pineal 5‐HT, also blocked any further decrease caused by treatment with l‐NE, an indication that protein synthesis is necessary for maintenance of baseline levels of serotonin and for the effect of l‐NE to be observed. The total amount of l‐[3H]NE and degradation products of L‐[3H]NE in the gland after 6 h of treatment with l‐[3H]NE was less than 3 pmol. This amount of l‐NE and degradation products of l‐NE could not account for the decrease of 100‐200 pmol of 5‐HT on the basis of a mole for mole replacement of 5‐HT by l‐NE. These findings are consistent with the hypothesis that non‐neuronal pineal 5‐HT is physiologically regulated by the release of l‐NE from the sympathetic nerve network.
EFFECT OF STRESS ON THE UPTAKE OF RADIOLABELLED CALCIUM IN THE PITUITARY GLAND AND THE BRAIN OF THE RAT
Authors: Sabbot Irene , Costin Anatol
Published: October 2006

The in vivo uptake of 45Ca by certain areas of the rat brain and by the pituitary gland was investigated under normal conditions and in states of cold stress. The uptake of 45Ca was highest in the pituitary gland followed in decreasing order by the superior colliculus, medulla, cerebellum, thalamus, hippocampus and the cortex. Cold stress conditions induced an increase in uptake of 45Ca in the cortex, hippocampus, cerebellum, medulla and the pituitary gland. Our findings suggest that cold stress induces a change in the permeability for calcium in blood‐brain and blood‐pituitary barriers.
SERUM TRYPTOPHAN BINDING IN CHLORPROMAZINE‐TREATED CHRONIC SCHIZOPHRENICS
Authors: Bender D. A. , Bamji A. N.
Published: October 2006

In ten hospitalized chronic schizophrenics receiving large doses of chlorpromazine and orphenadrine, the total serum tryptophan was approx. 50 per cent of normal. However, the level of diffusible tryptophan (that fraction directly available for uptake into the brain and other tissues) did not suffer so great a reduction, because the number of sites available for tryptophan binding per mole of serum albumin was only half that normally found, although the apparent affinity of the albumin for tryptophan was approximately normal. There was thus a considerable difference in the ratio of diffusible/bound serum tryptophan between the normal and schizophrenic subjects. Reduced serum albumin and elevated serum non‐esterified fatty acid levels in the schizophrenics do not appear to account for the abnormality of binding. In vitro and animal experiments with the two drugs chlorpromazine and orphenadrine suggested that the effects observed were not due to the drugs per se.
NORADRENALINE IN THE GUINEA PIG ALIMENTARY CANAL: REGIONAL DISTRIBUTION AND SENSITIVITY TO DENERVATION AND RESERPINE
Authors: Juorio A. V. , Gabella G.
Published: October 2006

The concentrations of noradrenaline, dopamine and 5‐hydroxytryptamine were studied in the stomach, duodenum, ileum, caecum (taenia coli), colon and rectum of the guinea pig. The wall of the alimentary canal was dissected into two fractions, one formed by the longitudinal muscle and myenteric plexus, the other formed by circular muscle, submucous plexus, submucosa and mucosa. In the longitudinal muscle‐myenteric plexus, the amount of noradrenaline was lower in the ileum (0.56 μg/g of fresh tissue), higher in the duodenum and caecum (0.75 μg/g and 0.82 μg/g respectively) and even higher in the stomach and rectum (0.85 μg/g and 0.91 μg/g). The highest value was found in the colon (1.33 μg/g), probably related to the occurrence of intramural adrenergic neurons.

When extrinsic nerves to the ileum were damaged, the amount of noradrenaline in the corresponding ileal segment was reduced to less than 5 per cent within 3 days in both fractions of the wall. 6‐Hydroxydopamine (35 mg/kg intravenously) reduced to approx. one‐third the amount of noradrenaline in longitudinal muscle‐myenteric plexus of ileum and colon. Reserpine (1 mg/kg, subcutaneously injected 72 h‐earlier) reduced the amount of noradrenaline in the longitudinal muscle‐myenteric plexus of both ileum and colon to 0.01 μg/g. Doses of reserpine as small as 0.02 mg/kg were still effective in causing a great reduction in noradrenaline concentration. No difference in the effects on ileum and colon was observed.
GLYCOSYL TRANSFERASE ACTIVITY IN NORMAL AND SCRAPIE‐AFFECTED MOUSE BRAIN
Authors: Suckling A. J. , Hunter G. D.
Published: October 2006

—The conditions required for the optimal activity of several glycosyl transferases were determined in normal and scrapie‐affected mouse brain. Particulate preparations were analysed for fucosyl, galactosyl, mannosyl and N‐acetyl glucosaminyl transferase activity using endogenous acceptors. Solubilized preparations were analysed for fucosyl, galactosyl and sialyl transferase activity using defined exogenous acceptors. The activity of each of these enzymes was followed at intervals throughout the development of scrapie in the mouse. In the endogenous system no change was found in the fucosyl and mannosyl transferase activities of the scrapie material, but the levels of galactosyl and N‐acetyl glucosaminyl transferase began to rise as clinical signs of scrapie developed i.e. at 15–16 weeks post‐inoculation. In the exogenous system the levels of galactosyl and fucosyl transferase began to rise in the scrapie material at 11–12 weeks post‐inoculation, rising to twice the normal value at 18–20 weeks. Sialyl transferase showed no change in activity.
ANTIGEN‐ANTIBODY CROSSED ELECTROPHORESIS OF RAT BRAIN SYNAPTOSOMES AND SYNAPTIC VESICLES: CORRELATION TO WATER‐SOLUBLE ANTIGENS FROM RAT BRAIN
Authors: Bock Elisabeth , Josrgensen O. S. , Morris S. J.
Published: October 2006

—Antigen‐antibody crossed electrophoresis has been applied to the study of rat brain synaptosomes and synaptic vesicles. Several antigens could be visualized. By comparison with previously describéd water‐soluble antigens from rat brain, some of the antigens in the synaptosome and the synaptic vesicle preparations were identified; among these were antigens which have been determined as brain‐specific. Furthermore, the antisera against the two subcellular fractions were compared with the anti‐serum against water‐soluble antigens from rat brain.
BIOSYNTHESIS OF FREE AMINO ACIDS IN THE BRAIN OF JIMPY MICE
Authors: Simler S. , Owsianowski N. , Randrianarisoa H. , Ledig M. , Mandel P.
Published: October 2006

—The metabolism of free amino acids: γ‐aminobutyric acid (GABA), glutamine, glycine and glutathione has been studied. The labelling of these free amino acids in normal and in myelin‐deficient brains of Jimpy mice was followed after intraperitoneal injection of 14C‐labelled glucose precursor. The quantitative distribution of these amino acids in the two kinds of mouse brain has been compared. A higher level of GABA and a faster labelling of the amino acids in Jimpy than in normal mouse brain was observed.
APPEARANCE OF GAMMA AMINOBUTYRATE TRANSAMINASE ACTIVITY IN DEVELOPING RAT BRAIN
Authors: Hyde J. C. , Robinson N.
Published: October 2006

—The distribution, localization and changes in intensity of γ‐aminobutyrate transaminase (4‐aminobutyrate: 2‐oxoglutarate aminotransferase, EC 2.6.1.19) in rat brain have been studied during the first 20 days of postnatal life by a histochemical technique.

Enzyme activity at birth was seen only in Purkinje cells of the cerebellar cortex where it increased markedly during the first 20 days. A rapid increase in enzyme activity was seen in regions of the hind‐brain after 3 days but a slower increase was apparent in areas of the fore‐ and mid‐brain. The results indicated that by 10 days post‐partum nerve cell GABA‐T activity had developed in the majority of brain areas studied, while glial cell GABA‐T activity developed between 10 and 15 days post‐partum.

Evidence is presented which indicates that there is a discontinuous function of GABA‐T in the developing brain.
CHRONIC LYSERGIC ACID DIETHYLAMIDE ADMINISTRATION AND SEROTONIN TURNOVER IN VARIOUS REGIONS OF RAT BRAIN
Authors: Peters D. A. V.
Published: October 2006

—Acute injections of LSD (2 × 500 μg/kg) to rats resulted in evidence of a reduced 5‐hydroxytryptamine (5‐HT) turnover in all brain areas studied. In contrast, a much smaller dose of LSD (20 μg/kg) repeated daily for 1 month produced a significantly reduced turnover only in the midbrain area. The pons/medulla and forebrain areas showed small and not statistically significant increases in 5‐HT turnover.
SULPHATIDE SYNTHESIS IN ISOLATED OLIGODENDROGLIAL AND NEURONAL CELLS12
Authors: Benjamins J. A. , Guarnieri M. , Miller K. , Sonneborn M. , McKhann G. M.
Published: October 2006

—Cerebroside sulphotransferase activity in oligodendroglia from calf brain is 8‐fold greater per cell than in calf neurons isolated at the same time under similar conditions. However, neuronal cell fractions from calf or rat brain have significant sulphotransferase activity, and in neurons isolated from rat brain at various ages, the capacity to synthesize sulphatide increases during myelination. The neuronal and oligodendroglial enzymes have similar substrate specificities and pH optima. Less of the enzyme could be extracted with Triton X‐100 from the isolated cells than from microsomes prepared from whole brain.
UPTAKE AND RELEASE OF POSSIBLE FALSE TRANSMITTER AMINO ACIDS BY RAT BRAIN TISSUE1
Authors: Baldessarini R. J. , Yorke C.
Published: October 2006

—The uptake of l[14C]glutamine by a crude isolated nerve ending fraction of rat brain was found to be linear with time for at least 5 min, profoundly temperature‐dependent, apparently half‐saturated at a substrate concentration of 0·26 mm, partially inhibited by dinitrophenol and ouabain and elevated [K+], weakly Na+‐dependent, poorly inhibited by drugs which block uptake of biogenic amines and more strongly inhibited by glutamic acid (IC50= 0·5mm) than by aspartic acid, GABA, glycine or methionine. The [14C]glutamine taken up appeared to be associated with nerve endings and was released by membrane‐disruption; about 20 per cent was associated with free mitochondria. Glutamine, δ‐aminolevulinic acid and several other amino acids were poor inhibitors of [3H]GABA‐uptake; δ‐aminolevulinic acid was a poor inhibitor of [3H]glutamine‐uptake, whereas glutamine was a moderately effective competitive inhibitor (Ki= 1 mm). [14C]glutamine and [3H]GABA were released from brain slices by electrical stimulation or 50 mm K+, while labeled δ‐aminolevulinic acid, leucine, urea, amphetamine and tyramine were poorly released. [14C]glutamine was not released by unlabeled glutamate or several aromatic amines. We conclude that the neuropsychiatric features of porphyria are not likely due to a ‘false transmitter’ role for δ‐aminolevulinic acid although such a role for glutamine in hepatic encephalopathy or other neuropsychiatric diseases should be considered.
THE INFLUENCE OF FUNCTIONAL ALTERATION ON MONOAMINE OXIDASE AND CATECHOL‐O‐METHYL TRANSFERASE IN THE VISUAL PATHWAY OF RATS1
Authors: Bigl V. , Biesold D. , Weisz K.
Published: October 2006

—Rats were reared in complete darkness or under chronic stimulation with flashing light from birth to the age of 7 weeks. Light deprivation caused a significant increase in monoamine oxidase activity (measured with [14C]serotonin) of about 30 per cent in the structures of the visual pathway. Chronic stimulation with flashing light had no influence on the activity of monoamine oxidase in either visual or non‐visual structures. The activity of catechol‐O‐methyl transferase in the brain areas of light‐deprived rats was reduced, in light‐stimulated rats it was slightly increased. In mother rats kept together with their litters in either complete darkness or flashing light for 5 weeks no change in monoamine oxidase activity was observed. The activity of catechol‐O‐methyl transferase in mother rats kept in darkness was significantly decreased in all brain regions studied; in light‐stimulated animals the enzyme activity was not affected.
SEROTONIN DEFICIENCY IN EXPERIMENTAL HYPERPHENYLALANINEMIA
Authors: Loo Y. H.
Published: October 2006

Abstract— The mechanism of serotonin depletion was studied in the preweanling rat in which a chemical simulation of phenylketonuria had been induced by injections of p‐CPA and l‐PA. Experimental conditions were selected to effectively minimize the contribution by deficient tryptophan hydroxylation and 5‐HTP transport. Excessive degradation of 5‐HT in the hyperphenylalaninemic brain could be eliminated as a possible mechanism. The observed levels of cerebral 5‐HTP, 5‐HT, 5‐HIAA before and 1 h after 5‐HTP loading, with and without pargyline pretreatment, clearly demonstrate greatly diminished in vivo synthesis of 5‐HT in the hyperphenylalaninemic animal. This deficient synthesis could largely be accounted for by decreased activity of aromatic l‐amino acid decarboxylase measured in the high speed soluble supernatant extracts of whole brain. Decreased storage of 5‐HT in the particulate subcellular fraction of whole brain was also noted in the hyperphenylalaninemic animal. Significant lowering of bound serotonin levels in the brain occurred with injections of PEA into normal animals.
AXONAL TRANSPORT OF [3H]GLUCOSE RADIOACTIVITY IN THE OPTIC SYSTEM OF SCARDINIUS ERYTHROPHTHALMUS1
Authors: Breer H. , Rahmann H.
Published: October 2006

Abstract— The optic system of Scardinius erythrophthalmus has been used to study the axonal translocation of radioactivity from [3H]glucose. Intraocularly injected precursors were transported intra‐axonally along the optic nerve towards the contralateral optic tectum. In comparison with the well known properties of axonal protein transport there were remarkable differences in the proximo‐distal translocation of [3H]glucose. These were: (1) a delay in the labelling of the structures investigated, after tracer application; (2) only a rapid phase of transport; and (3) no accumulation of radioactivity in the region of nerve terminals in the optic tectum connected with the injected eye. The transported material was almost exclusively in the form of TCA‐soluble compounds and was mainly glucose itself or its low molecular derivatives, but not glycogen. The rate of transport was decreased by lowered temperatures and was not immediately dependent on retinal protein synthesis. Colchicine blocked the axonal transport of glucose by up to 60–70 per cent.
THE NORMAL OCCURRENCE OF OCTOPAMINE IN NEURAL TISSUES OF THE OCTOPUS AND OTHER CEPHALOPODS
Authors: Juorio A. V. , Molinoff P. B.
Published: October 2006

Abstract— An enzymatic assay was used to measure the concentration of octopamine in tissue of cephalopods. The concentration of octopamine varied over a wide range in neural tissues of Octopi and other cephalopods. The administration of reserpine caused a fall in the concentration of octopamine while monoamine oxidase inhibition caused the concentration to rise. After density gradient centrifugation octopamine was found in the same regions of the gradients as were dopamine and noradrenaline. These findings suggest that octopamine may be involved in neuronal function in cephalopods.
HIGH AFFINITY CHOLINE TRANSPORT IN GUINEA PIG BRAIN AND THE EFFECT OF NOREPINEPHRINE
Authors: Carroll Paul T. , Buterbaugh Gary G.
Published: October 2006

—The influence of 1‐norepinephrine on the accumulation of [14C]choline by nuclei‐free homogenates and synaptosomes of guinea‐pig brain was studied. Kinetic analysis of choline accumulation by guinea‐pig brain resulted in both high and low affinity Michaelis constants. Norepinephrine stimulated the high affinity choline transport process but not the low and the magnitude of its stimulation in 3 different brain regions was correlated with the choline acetyltransferase activity of those regions. Depletion of norepinephrine from the brainstem by pretreatment with the catecholamine depleter alpha‐methyl‐para‐tyrosine significantly decreased the maximal velocity of choline transport. Both the alpha adrenergic receptor blocker phentolamine and the beta adrenergic receptor blocker propranalol inhibited norepinephrine induced stimulation of choline transport. Cocaine stimulated choline transport at low concentrations and pretreatment of animals with reserpine significantly antagonized cocaine's stimulation of choline transport. The results suggest that endogenous norepinephrine may modify the high affinity choline transport process in guinea‐pig brain.
CERAMIDE GLYCOSYLTRANSFERASES IN CULTURED RAT CEREBELLUM: CHANGES WITH AGE, WITH DEMYELINATION, AND WITH INHIBITION OF MYELINATION BY 5‐BROMO‐2′‐DEOXYURIDINE OR EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS SERUM
Authors: Latovitzki N. , Silberberg D. H.
Published: October 2006

—UDP‐galactose:ceramide galactosyltransferase (CGalT) (E.C. 2.4.1.62) and UDP‐glucose:ceramide glucosyltransferase (CGlcT) activities were measured in myelinating cultures of newborn rat cerebellum. Specific activities were measured at various days in vitro and the pattern of activities compared with that reported for in vivo tissue. Cultures demyelinated by incubation with media containing 22% serum from rabbits in which experimental allergic encephalomyelitis (EAE) was induced by injection with whole guinea‐pig spinal cord, had 28% of CGalT specific activity and 86% of CGlcT specific activity measured in control cultures. Cultures in which myelination was inhibited by maintenance on media containing 0.15 mm‐5‐bromo‐2′‐deoxyuridine (BUdR) had 10% of CGalT specific activity and 118% of CGlcT specific activity of control cultures. Cultures in which myelination was inhibited by maintenance on media containing 2% EAE serum had 12% of the CGalT specific activity of control cultures. The data suggest that in vitro CGalT is predominantly a glial enzyme while CGlcT occurs primarily in neurons, and that the reduced CGalT activity may be involved in the mechanism of myelination inhibition by BUdR and by EAE serum.
DEOXYRIBONUCLEASES IN DEVELOPING AND ADULT RAT CEREBELLUM: TRANSIENT AND LONG DURATION ACTIONS OF METHYLAZOXYMETHANOL
Authors: Chanda Rita , Woodward D. J. , Griffin W. S. T.
Published: October 2006

—Acid and alkaline DNase activities were determined in postnatal and adult rat cerebellum. Normal animals were compared with those injected with 10 mg/kg methylazoxymethanol acetate using varying schedules after birth in order to induce transient damage to proliferating cell populations. In all animals studied, both immature and adult, methylazoxymethanol caused an increase in acidic and decrease in alkaline DNase activity. These effects were not specific to the dividing populations and occurred in nonmitotic cells as well. When injections were given to young adults, these effects appeared irreversible and persisted up to 3 months after birth.
STRUCTURAL ALTERATIONS OF AMINO ACIDS AT THE LEVEL OF AMINOACYL‐tRNAS: IDENTIFICATION OF THE TRANSFORMATION PRODUCTS OF DICARBOXYLIC AMINO ACIDS
Authors: Murthy M. R. V. , Thénot J. P. , Roux Huguette
Published: October 2006

Abstract— Glutamyl‐, glutaminyl‐, aspartyl‐ and asparaginyl‐tRNAs were separated into different isoacceptor species by reverse phase column chromatography. RNase hydrolysates of any of the isoacceptor [14C]aminoacyl‐tRNAs for a given amino acid gave radioactivity profiles, on paper electrophoresis, very similar to unfractionated tRNA. This suggested a lack of tRNA specificity for the transformation reaction involving the aminoacyl moieties of asparaginyl and glutaminyl‐tRNAs. GnP2 and AnP2 detected in the products of deaminoacylation of glutaminyl and asparaginyl‐tRNA showed a number of properties in common with GnE3 and AnE3 present in the RNase hydrolysates of the same tRNAs. Thus, GnP2 and GnE3 chromatographed in the same position in the phenol: water solvent and both yielded glutamate on acid hydrolysis and a mixture of glutamine and isoglutamine on alkaline hydrolysis. Similarly, AnP2 and AnE3 had the same RF value in phenol :water chromatography and gave aspartate or a mixture of asparagine and isoasparagine when hydrolyzed with acid or alkali. On the basis of these results and other evidence, GnP2 and GnE3 were assigned the structure, α‐aminoglutarimide; AnP2 and AnE3 were identified as α‐aminosuccinimide. These cyclic compounds are presumed to be formed by nucleophilic attack of the amide nitrogen of asparagine or glutamine on the carbon of the aminoacyl ester carbonyl group. The cyclization‐deesterification appeared to be facilitated by RNase hydrolysis of aminoacyl‐tRNA indicating that the aminoacyl‐tRNA is probably more resistant to this reaction than aminoacyladenosine. Neither the imides nor the amino acid isoamides were detected in the reaction mixture in which aminoacylation of tRNA was performed, suggesting that a mechanism may exist for inhibition of the cyclization reaction under conditions of active aminoacylation.
THE METABOLISM OF LABELLED ETHANOLAMINE IN NEURONAL AND GLIAL CELLS OF THE RABBIT IN VIVO1
Authors: Goracci G. , Francescangeli E. , Piccinin G. L. , Binaglia L. , Woelk H. , Porcellati G.
Published: October 2006

Abstract— Adult rabbits were injected intraventricularly with [14C]ethanolamine and the incorporation of the base into the phosphatidylethanolamine and ethanolamine plasmalogen (and their water‐soluble precursors) of isolated neuronal and glial cells was investigated. All the radioactivity was incorporated into the base moiety of the ethanolamine lipids for the time intervals examined in both types of cells. In neurons, maximum labelling of the two ethanolamine lipids occurred at 7 h after administration, whereas the highest specific radioactivity for glial phosphatidylethanolamine and ethanolamine plasmalogen was reached at 20 and 36 h, respectively. The two lipids had a faster turnover in neurons than in glia, and in both populations incorporated the base at a faster rate than did whole brain tissue. The maximum incorporation rates for phosphorylethanolamine and CDP‐ethanolamine were reached in both types of cell at about 6 h after administration but the content of radioactivity per unit protein for phosphorylethanolamine was much higher in glial than in neuronal cells. It is concluded that the site of most active synthesis of ethanolamine phospholipids in vivo is the neuronal cell, with a possible transfer of intact lipid molecule to the glial compartment.
CEREBRAL AROMATIC AMINOTRANSFERASE
Authors: Noguchi T. , Nakatani M. , Minatogawa Y. , Okuno E. , Kido R.
Published: October 2006

—Aromatic: 2‐oxoglutarate aminotransferase has been purified about 950‐fold from rat brain mitochondria. The purified enzyme was homogeneous in polyacrylamide gel electrophoresis and had a molecular weight of approx 63,000. On the basis of substrate specificity, substrate inhibition, purification ratio, yield, polyacrylamide gel electrophoresis and some other properties of the enzyme it has been suggested that brain mitochondrial tyrosine:2‐oxoglutarate aminotransferase (l‐tyrosine: 2‐oxoglutarate aminotransferase, EC 2.6.1.5) is identical with brain mitochondrial phenylalanine and kynurenine: 2‐oxoglutarate aminotransferases (l‐kynurenine: 2‐oxoglutarate aminotransferase, EC 2.6.1.7), and also with aspartate: 2‐oxoglutarate aminotransferase (l‐aspartate: 2‐oxoglutarate aminotransferase, EC 2.6.1.1).