Intra- and extraneuronal monoamineoxidase-A and -B activities after central axotomy (hemisection) on rats

Stenström, Anders; Arai, Yasuhiko; Oreland, L.

doi:10.1007/bf01253055

Cited by 42 publications

(14 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This was also found here for MAO-B in the aged rat forebrain (Vmax, 110% and concentration, 124%) even with age-related independent changes in total protein, MAO-A and -B activity in rat brain (Strolin Benedetti and Keane, 1980). The present results thus lead us hypothesize that the increase in rat brain MAO-B activity by treatment with hemitransection (Oreland et al, 1980;Stenstrom et al, 1985) might be a result of increased numbers of MAO-B molecules. This correlation between the increase OfVma x and the concentration of MAO-B was also found for aged human brain (Fowler et al, 1980c).…”

Section: Resultssupporting

confidence: 80%

Differences between monoamine oxidase concentrations in striatum and forebrain of aged and young rats

Arai

Kinemuchi

1988

J. Neural Transmission

Self Cite

View full text Add to dashboard Cite

The MAO-A and MAO-B activities in the striatum and the rest of the forebrain of young adult and aged rats were determined and compared. There was no significant difference in Km values of MAO-A for 5-HT or of -B for benzylamine in any of the brain regions of both rat groups. With increase in age, the Vmax value of MAO-A in the forebrain decreased; in the striatum the Vmax values of MAO-A and -B increased with age. The MAO-A concentrations, measured by enzyme titration with clorgyline or 1-deprenyl as the titre, were the same in both brain regions of young and aged rats, but in both brain regions of aged rats, MAO-B concentrations were greater than those in young rats. The MAO-B concentrations increased in parallel with the increases in Vmax indicating that the increase with age was due to increase in the number of MAO molecules.

show abstract

Section: Resultssupporting

confidence: 80%

Differences between monoamine oxidase concentrations in striatum and forebrain of aged and young rats

Arai

Kinemuchi

1988

J. Neural Transmission

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thus, cerebral blood flow can be studied with oxygen-15 labelled water, and changes in glucose metabolism measured by the uptake of fluor-18 2-fluorodeoxyglucose (FDG) may serve as a marker of neuronal dysfunction and death. Furthermore, N-[ 11 C-methyl]-L-deuterodeprenyl (DED), a MAO-B inhibitor, has been shown to be a useful marker of astrocytosis/gliosis [10,11,12,13,14]. Together these three tracers might be of value for the diagnosis of TSE.…”

Section: Introductionmentioning

confidence: 97%

Multitracer study with positron emission tomography in Creutzfeldt-Jakob disease

Engler

Lundberg

Ekbom

et al. 2003

European Journal of Nuclear Medicine and Molecular Imaging

View full text Add to dashboard Cite

During the period February 1997 to April 2000, 15 patients with clinical symptoms of Creutzfeldt-Jakob disease (CJD) were referred to Uppsala University PET Centre. Positron emission tomography (PET) was performed to detect characteristic signs of the disease, e.g. neuronal death and/or astrocytosis in the brain. The examinations were performed in one session starting with oxygen-15 labelled water scan to measure regional cerebral blood flow, followed by imaging with the monoamine oxidase B inhibitor N-[(11)C-methyl]- L-deuterodeprenyl (DED) to assess astrocytosis in the brain and finally imaging with fluor-18 2-fluorodeoxyglucose (FDG) to assess regional cerebral glucose metabolism (rCMR(glu)) [corrected]. Nine of the patients fulfilled the clinical criteria of probable CJD. In eight of them, FDG and DED imaging revealed, in comparison with normal controls, a typical pattern characterized by a pronounced regional decrease (<2SD) in glucose brain metabolism, indicative of neuronal dysfunction; this was accompanied by a similar increase (>2SD) in DED binding, indicating astrocytosis. These changes were most pronounced in the cerebellum and the frontal, occipital and parietal cortices, whereas the pons, the thalamus and the putamen were less affected and the temporal cortex appeared unaffected. The cerebral blood flow showed a pattern similar to that observed with FDG. In the ninth patient, analysis with DED was not possible. The diagnosis of definite CJD according to international consensus criteria was confirmed in six of these patients. In one patient with probable CJD, protease-resistant prion protein (PrPres) could not be demonstrated. In two patients with probable CJD, autopsy was not allowed. Computed tomography and magnetic resonance imaging, performed in four and seven of these nine patients respectively, showed unspecific, mainly atrophic changes. In six other patients, the PET examinations gave a different pattern. In three of them, high rCMR(glu) was noticed in parts of the brain, particularly in the temporal lobes and basal ganglia, which could suggest encephalitis. One of the patients had Sjögren's syndrome, one had paraneoplastic limbic encephalitis and the third recovered spontaneously. In the other three patients, the DED binding was normal despite a hypometabolic glucose pattern. In conclusion, the PET findings obtained using DED and FDG paralleled neuropathological findings indicating neuronal dysfunction and astrocytosis, changes that are found in CJD.

show abstract

“…MAO-A and -B activities within and outside the noradrenergic and dopaminergic synaptosomes were determined essentially as de-scribed previously for other species (Ask et al 1983(Ask et al & 1985Oreland et al 1983;Stenstrom et al 1985Stenstrom et al & 1987. Briefly, aliquots of the homogenates (300 pl when using NA, 50 p1 when using DA) were preincubated for 5 (fig.…”

Section: Methodsmentioning

confidence: 99%

Comparison of Intra‐ and Extrasynaptosomal Monoamine Oxidase‐A and ‐B Activities in the Striatum and Frontal Cortex of Two Mice Strains with Different Sensitivities to the Neurotoxic Actions of 1‐Methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine

Stenström

Sundström

Fowler

1989

Pharmacology & Toxicology

View full text Add to dashboard Cite

Conditions for the assay of the intra- and extrasynaptosomal rates of deamination of dopamine and noradrenaline by the two forms of monoamine oxidase (MAO) have been determined in striatal and frontal cortical homogenates, respectively, from C57 BL/6 mice. The activities obtained were compared with the corresponding activities found for NMRI mice, a strain less sensitive to the neurotoxic effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) than the C57 BL/6 strain. In both strains, the intra- and extrasynaptosomal deamination of dopamine in the striatal homogenates was brought about predominantly by MAO-A. No significant differences between the two strains were found for the intra- or extrasynaptosomal MAO-A or -B activities towards dopamine in striatal homogenates. On the other hand, the striatal dopamine concentrations were higher in the C57 BL/6 mice than in the NMRI mice. The concentrations of the dopamine metabolites DOPAC and HVA were similarly higher, suggesting that the rate of turnover of dopamine is the same for the two strains. In frontal cortical homogenates, MAO-A predominated in the deamination of noradrenaline both intra- and extrasynaptosomally. The extrasynaptosomal rates of deamination of noradrenaline were similar in the two mice strains, whereas the intrasynaptosomal MAO-A activity was significantly higher for the C57 BL/6 mice. These results concur with and extend to the noradrenergic system the conclusion previously made by Jossan et al. (1987) for the dopaminergic system that although MAO-B activity is necessary for expression of MPTP neurotoxicity, it is not the rate-limiting step for the development of the neurotoxic effects.

show abstract

Intra- and extraneuronal monoamineoxidase-A and -B activities after central axotomy (hemisection) on rats

Cited by 42 publications

References 23 publications

Differences between monoamine oxidase concentrations in striatum and forebrain of aged and young rats

Differences between monoamine oxidase concentrations in striatum and forebrain of aged and young rats

Multitracer study with positron emission tomography in Creutzfeldt-Jakob disease

Comparison of Intra‐ and Extrasynaptosomal Monoamine Oxidase‐A and ‐B Activities in the Striatum and Frontal Cortex of Two Mice Strains with Different Sensitivities to the Neurotoxic Actions of 1‐Methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine

Contact Info

Product

Resources

About