scholarly journals The biosynthesis of brain gangliosides. Ganglioside-glycosylating activity in rat brain neuronal perikarya fraction

1978 ◽  
Vol 174 (3) ◽  
pp. 673-680 ◽  
Author(s):  
H J F Maccioni ◽  
S S Defilpo ◽  
C A Landa ◽  
R Caputto
Keyword(s):  
Rat Brain ◽  
Time Course ◽  
Brain Homogenate ◽  
Acetylneuraminic Acid ◽  
Synaptosomal Fraction ◽  
Old Rats ◽  
Brain Gangliosides

Rat brain homogenate and the synaptosmal and neuronal perikarya fractions from 17-day-old rats were compared for their activities in sialosylating endogenous gangliosides and transferring N-acetylneuraminic acid and galactose to several glycolipids in vitro. The sialosylation of endogenous gangliosides and the activities of sialosyltransferases acting either on lactosylceramide or haematoside as acceptors, as well as galactosyltransferase acting on Tay-Sachs ganglioside as acceptor, were between 3-and 12-fold higher in the neuronal perikarya fraction than in whole homgenate on a protein or ganglioside basis. The activities found in the synaptosomal fraction were negligible. No evidence was found to indicate that the low activities in this fraction were due to the presence of inhibitors of the transfer activities or to inacessibility of the substrates to their respective enzymes. These findings, and the time course of labelling of gangliosides of the neuronal perikarya and synaptosomes from rats that received an injection of N-[3H]acetylmannosamine, indicate that the main cellular site of glycosylation of neuronal gangliosides is in the neuronal perikarya.

scholarly journals The biosynthesis of brain gangliosides. Separation of membranes with different ratios of ganglioside sialylating activity to gangliosides

1977 ◽  
Vol 168 (3) ◽  
pp. 325-332 ◽  
Author(s):  
C A Landa ◽  
H J F Maccioni ◽  
A Arce ◽  
R Caputto
Keyword(s):  
Membrane Fraction ◽  
Time Course ◽  
Mitochondrial Fraction ◽  
Subcellular Fractions ◽  
Synthetase Activity ◽  
Acetylneuraminic Acid ◽  
Mitochondrial Fractions ◽  
Brain Gangliosides

Brain subcellular fractions were analysed for ganglioside-sialylating activity by measuring the incorporation of N-[3H]acetylneuraminic acid from CMP-N-[3H]acetylneuraminic acid into endogenous ganglioside acceptors (endogenous incorporation) and into exogenous lactosyceramide (haematoside synthetase activity). The ratios of endogenous incorporation to gangliosides and of haematoside synthetase to gangliosides for the synaptosomal and mitochondrial fractions from a washed crude mitochondrial fraction were lower than those obtained for other membrane fractions. The differences appear to reflect intrinsic characteristics of each membrane fraction. The results of labelling in vitro and the time course of labelling of gangliosides of the different subcellular fractions in vivo after injection of N-[3H]acetylmannosamine are consistent with the possibility of a subcellular site for synthesis of gangliosides different from that of ganglioside deposition.

scholarly journals The biosynthesis of gangliosides. Labelling of rat brain gangliosides in vivo

1971 ◽  
Vol 125 (4) ◽  
pp. 1131-1137 ◽  
Author(s):  
H. J. Maccioni ◽  
A. Arce ◽  
R. Caputto
Keyword(s):  
Rat Brain ◽  
The Other ◽  
Total Brain ◽  
Old Rats ◽  
Brain Gangliosides ◽  
Ceramide Moiety

1. After injection of [6-3H]glucosamine into 8-day-old rats it was found that all the major brain gangliosides and their sialyl groups were labelled at essentially the same rate, except the hematoside, which was the least labelled. In 18-day-old rats it was found that the two major gangliosides with the sialyl (2→8)-sialyl linkage, and their sialyl groups were more labelled than the hematoside, the Tay–Sachs ganglioside, the other two major gangliosides and their respective sialyl groups. 2. No difference was found in any of the cases studied between the specific radioactivities of the neuraminidase-resistant and -labile sialyl groups belonging to the same ganglioside. The same was found for the specific radioactivities of the galactosyl groups proximal and distal to the ceramide moiety of total brain gangliosides from rats injected with [U-14C]glucose. From this it was concluded that partial turnover of the ganglioside molecule does not occur. 3. A model for the synthesis of gangliosides is presented that accounts for results from previous experiments in vitro and the lack of precursor–product relationships observed in experiments in vivo.

In vitro anticholinesterase, antimonoamine oxidase and antioxidant properties of alkaloid extracts from kola nuts (Cola acuminata and Cola nitida)

2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Ganiyu Oboh ◽  
Ayokunle O. Ademosun ◽  
Opeyemi B. Ogunsuyi ◽  
Esther T. Oyedola ◽  
Tosin A. Olasehinde ◽  
...  
Keyword(s):  
Side Effects ◽  
Neurodegenerative Diseases ◽  
Rat Brain ◽  
Brain Homogenate ◽  
Oh Radicals ◽  
Mao Inhibitors ◽  
Alkaloid Extracts ◽  
Cola Nitida ◽  
Cola Acuminata

Abstract Background The development of cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors for management of neurodegenerative diseases such as Alzheimer’s disease (AD) has come with their undesirable side effects. Hence, research for potent but natural ChE and MAO inhibitors with little or no side effects is essential. This study investigated the potentials of alkaloid extracts from two Cola species as nutraceuticals for prevention and management of AD. Methods Alkaloid extracts were obtained from two Cola species (Cola nitida [KN] and Cola acuminata [KA]) by solvent extraction method. The extracts were characterized for their alkaloid contents using gas chromatography (GC). The effects of the extracts on ChE and MAO activities were investigated in vitro. Also, the extracts’ ability to inhibit Fe2+-induced lipid peroxidation in rat brain homogenate, scavenge DPPH and OH radicals, as well as chelate Fe2+ were determined. Results GC characterization revealed the presence of augustamine and undulatine as the predominant alkaloids in the extracts. There was no significant (P > 0.05) difference in the inhibitory effects of the extracts on ChE activities. However, KA extract exhibited significantly higher (P < 0.05) MAO inhibitory effect than KN. Also, KA extract inhibited Fe2+- induced malondialdehyde (MDA) production in rat brain homogenate more significantly than KN, while there was no significant difference in DPPH and OH radicals scavenging, as well as Fe2+-chelating abilities of the extracts. Conclusions Our findings revealed that KN and KA alkaloid extracts exhibited significant effect in vitro on biological pathways that may contribute to neuroprotection for the management of neurodegenerative diseases.

scholarly journals Rat brain microsomal gangliosides. Accessibility to a neuraminidase preparation and the possible existence of different pools in relation to their biosynthesis

1974 ◽  
Vol 138 (2) ◽  
pp. 291-298 ◽  
Author(s):  
H. J. F. Maccioni ◽  
A. Arce ◽  
C. Landa ◽  
R. Caputto
Keyword(s):  
Rat Brain ◽  
Chemical Structure ◽  
Proper Position ◽  
Neuraminidase Treatment ◽  
Acetylneuraminic Acid ◽  
Microsomal Membranes ◽  
Labelling Experiment ◽  
Labile N ◽  
The Right

1. Treatment of rat brain microsomal membranes with a neuraminidase preparation from Clostridium perfringens resulted in an almost complete conversion of polysialogangliosides into monosialogangliosides. 2. Neuraminidase treatment of the membranes did not increase the incorporation of N-[3H]acetylneuraminic acid from CMP-N-[3H]acetylneuraminic acid into the gangliosidic fraction, indicating that a monosialoganglioside is an acceptor of N-acetylneuraminic acid in these membranes only if, in addition to having the right chemical structure, it is in a proper position, probably in relation to the endogenous sialyltransferases. 3. These experiments also indicated that no independent turnover of the neuraminidase-labile N-acetylneuraminyl groups of gangliosides occurred in vitro. 4. N-[3H]Acetylneuraminic acid from endogenous polysialogangliosides labelled in vitro was released by neuraminidase at a slower rate than N-acetylneuraminic acid from unlabelled gangliosides of the same membranes. From this it was concluded that recently synthesized polysialogangliosides (completed in vitro) are in the membranes in a position less accessible to neuraminidase than are those synthesized earlier which were present in the membranes at the start of the labelling experiment.

Organotypic slice cultures from rat brain tissue: a new approach forNaegleria fowleriCNS infectionin vitro

Parasitology ◽  
2005 ◽  
Vol 132 (6) ◽  
pp. 797-804 ◽  
Author(s):  
C. GIANINAZZI ◽  
M. SCHILD ◽  
N. MÜLLER ◽  
S. L. LEIB ◽  
F. SIMON ◽  
...  
Keyword(s):  
Animal Models ◽  
Rat Brain ◽  
Time Course ◽  
Ethical Issues ◽  
Brain Morphology ◽  
Specific Morphology ◽  
Organ Specific ◽  
Organotypic Slice Cultures

The free-living amoebaNaegleria fowleriis the aetiological agent of primary amoebic meningoencephalitis (PAM), a disease leading to death in the vast majority of cases. In patients suffering from PAM, and in corresponding animal models, the brain undergoes a massive inflammatory response, followed by haemorrhage and severe tissue necrosis. Both,in vivoandin vitromodels are currently being used to study PAM infection. However, animal models may pose ethical issues, are dependent upon availability of specific infrastructural facilities, and are time-consuming and costly. Conversely, cell cultures lack the complex organ-specific morphology foundin vivo, and thus, findings obtainedin vitrodo not necessarily reflect the situationin vivo. The present study reports infection of organotypic slice cultures from rat brain withN. fowleriand compares the findings in this culture system within vivoinfection in a rat model of PAM, that proved complementary to that of mice. We found that brain morphology, as presentin vivo, is well retained in organotypic slice cultures, and that infection time-course including tissue damage parallels the observationsin vivoin the rat. Therefore, organotypic slice cultures from rat brain offer a newin vitroapproach to studyN. fowleriinfection in the context of PAM.

scholarly journals Antioxidative Activity of Ferrocenes Bearing 2,6-Di-Tert-Butylphenol Moieties

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
E. R. Milaeva ◽  
S. I. Filimonova ◽  
N. N. Meleshonkova ◽  
L. G. Dubova ◽  
E. F. Shevtsova ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Rat Brain ◽  
Antioxidative Activity ◽  
Neuroprotective Effect ◽  
In Vitro Study ◽  
Brain Homogenate ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Calcium Dependent

The antioxidative activity of ferrocenes bearing either 2,6-di-tert-butylphenol or phenyl groups has been compared using DPPH (1,1-diphenyl-2-picrylhydrazyl) test and in the study of the in vitro impact on lipid peroxidation in rat brain homogenate and on some characteristics of rat liver mitochondria. The results of DPPH test at20∘C show that the activity depends strongly upon the presence of phenolic group but is improved by the influence of ferrocenyl fragment. The activity of N-(3,5-di-tert-butyl-4-hydroxyphenyl)iminomethylferrocene (1), for instance, was 88.4%, which was higher than the activity of a known antioxidant 2,6-di-tert-butyl-4-methylphenol (BHT) (48.5%), whereas the activity of N-phenyl-iminomethylferrocene2was almost negligible−2.9%. The data obtained demonstrate that the compounds with 2,6-di-tert-butylphenol moiety are significantly more active than the corresponding phenyl analogues in the in vitro study of lipid peroxidation in rat brain homogenate. Ferrocene1performs a promising behavior as an antioxidant and inhibits the calcium-dependent swelling of mitochondria. These results allow us to propose the potential cytoprotective (neuroprotective) effect of ditopic compounds containing antioxidant 2,6-di-tert-butylphenol group and redox active ferrocene fragment.

scholarly journals Effect of hyperphenylalaninaemia on lipid synthesis from ketone bodies by rat brain

1976 ◽  
Vol 154 (2) ◽  
pp. 319-325 ◽  
Author(s):  
M S. Patel ◽  
O E. Owen
Keyword(s):  
Rat Brain ◽  
Ketone Bodies ◽  
Brain Slices ◽  
Lipid Synthesis ◽  
Coa Transferase ◽  
Old Rats ◽  
And Function ◽  
Developing Rat

The effect of hyperphenylalaninaemia on the metabolism of ketone bodies in vivo and in vitro by developing rat brain was investigated. The incorporation in vivo of [14C]acetoacetate into cerebral lipids was decreased by both chronic (for 3 days) and acute (for 6h) hyperphenylalaninaemia induced by injecting phenylalanine into 1-week-old rats. In studies in vitro it was observed that the incorporation of the radioactivity from [14C]acetoacetate and 3-hydroxy[14C]butyrate into cerebral lipids was inhibited by phenyl-pyruvate, but not by phenylalanine. Phenylpyruvate also inhibited the incorporation of 3H from 3H2O into lipids by brain slices metabolizing either 3-hydroxybutyrate or acetoacetate in the presence of glucose. These findings suggest that the decrease in the incorporation in vivo of [14C]acetoacetate into cerebral lipids in hyperphenylalaninaemic rats is most likely caused by phenylpyruvate and not by phenylalanine. Phenylpyruvate as well as phenylalanine had no inhibitory effects on ketone-body-catabolizing enzymes, namely 3-hydroxybutyrate dehydrogenase, 3-oxo acid CoA-transferase and acetoacetyl-CoA thiolase, in rat brain. Phenylpyruvate but not phenylalanine inhibited the activity of the 2-oxoglutarate dehydrogenase complex from rat and human brain. These findings suggest that the metabolism of ketone bodies is impaired in brains of untreated phenylketonuric patients, and in turn may contribute to the diminution of mental development and function associated with phenylketonuria.

PRODUCTION OF TESTOSTERONE, 5α-ANDROSTANE-3α,17β-DIOL AND ANDROSTERONE BY DISPERSED TESTICULAR INTERSTITIAL CELLS AND WHOLE TESTES IN VITRO

1979 ◽  
Vol 80 (3) ◽  
pp. 321-332 ◽  
Author(s):  
W. H. MOGER
Keyword(s):  
Luteinizing Hormone ◽  
Time Course ◽  
Interstitial Cells ◽  
Total Production ◽  
Testosterone Production ◽  
Testicular Interstitial Cells ◽  
Old Rats ◽  
Linear Manner ◽  
Predominant Product

The production of 5α-androstane-3α,17β-diol (androstanediol), androsterone and testosterone by whole rat testes and testicular interstitial cells dispersed with collagenase was studied in vitro. Luteinizing hormone stimulated the production of each of the androgens by cells prepared from 31- to 34-day-old rats. Half maximum stimulation of the production of each androgen occurred with approximately 3·5 ng NIH-LH-B9/ml medium. Androstanediol was the predominant product then androsterone and then testosterone. Luteinizing hormone stimulated the production of testosterone, but not androstanediol or androsterone by dispersed interstitial cells from 200-day-old rats. The time-course of production and the effect of the concentration of cells on the production of these androgens suggested that in dispersed testicular interstitial cells from immature animals androstanediol and androsterone are formed, at least partially, by the metabolism of testosterone. In these experiments LH-stimulated testosterone production increased during incubation for 15–60 min and then remained constant up to 180 min. The concentrations of androstanediol and androsterone increased in a linear manner during incubation for 60–180 min. Varying the number of cells incubated yielded a positive correlation between cell concentration and the ratio 5α-reduced androgen: testosterone produced. Luteinizing hormone stimulated production of each androgen by whole testes obtained from rats at 30–175 days of age. The serum concentration of testosterone in these rats increased abruptly at 50 days of age. Significant changes in androgen production in vitro also observed at this age included: (1) increased production of the three steroids when incubated in either the presence or absence of LH and (2) testosterone production, either in the presence or absence of LH, which represented a greater percentage of the total production of the three androgens.

Time course of in vitro expression of NADPH-diaphorase in cultured rat brain neurons: comparison with in vivo expression

1991 ◽  
Vol 59 (2) ◽  
pp. 157-162 ◽  
Author(s):  
Yukiko Uehara-Kunugi ◽  
Kazuhiro Terai ◽  
Takashi Taniguchi ◽  
Ikuo Tooyama ◽  
Hiroshi Kimura
Keyword(s):  
Rat Brain ◽  
Time Course ◽  
Nadph Diaphorase ◽  
Brain Neurons ◽  
In Vitro Expression ◽  
In Vivo Expression ◽  
Rat Brain Neurons
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