Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A competitive antagonist of the N-methyl-D-aspartate receptor, CGP 39551, was administered daily to neonatal rats with increasing doses from postnatal day 1 to 22. These animals displayed approximately 50% decrease of body weight at the end of treatment and, therefore, both normal and neonatally undernourished rats were used as controls. At a young adult stage (55-75 days of age) CGP 39551-treated rats showed a much higher spontaneous locomotor activity as compared to control groups. This hypermotility was counteracted by D1 and D2 dopamine antagonists while administration of methamphetamine increased, to the same extent, the differential basal locomotor activity of treated and control groups. The locomotor activity response to the N-methyl-D-aspartate channel blocker, dizocilpine maleate, was significantly shifted to the right for treated rats so that an equivalent increase of motility was obtained by doubling the dose effective for control animals. In in vivo microdialysis experiments, similar amounts of dopamine were collected from the striatum of treated and control rats after high K+ or methamphetamine stimulation, the only difference being a greater Ca2+ dependency of the depolarization-induced dopamine release in treated rats. Assays for different neurochemical parameters, carried out at 80-90 days of age, suggested some alteration of the balance between excitatory and inhibitory circuits in the basal ganglia of CGP 39551-treated rats. Tyrosine hydroxylase and calbindin immunostaining, as well as acetylcholinesterase histochemistry, revealed a similar picture in the striatum of treated and control rats. However, 5'-nucleotidase histochemistry showed a stronger and evenly distributed reactivity in the striatum of treated rats, opposite to the weaker and patchy localization of normal or undernourished controls. From the present results it is possible to conclude that chronic blockade of the N-methyl-D-aspartate receptor during neonatal brain maturation results in long-lasting alteration of locomotor activity which appears related to functional changes of the dopamine receptors as well as to an altered balance between various excitatory and inhibitory neurotransmitter and neuromodulatory systems.
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PMID:Long-lasting effects of chronic neonatal blockade of N-methyl-D-aspartate receptor through the competitive antagonist CGP 39551 in rats. 791 9

The glycoprotein 5'-nucleotidase is a cell surface phosphatase and represents a new marker for striosomes in the adult rat caudoputamen. We report here on its developmental expression in the rat and mouse striatum, and show an unexpected converse 5'-nucleotidase chemoarchitecture of the caudoputamen in these closely related species. In the rat, 5'-nucleotidase activity was first visible as neuropil staining in tyrosine hydroxylase-positive dopamine islands of the midstriatum on postnatal day 1, and by the end of the first postnatal week, 5'-nucleotidase-positive dopamine islands also appeared rostrally. This compartmental pattern persisted thereafter, so that in adult animals, in all but the caudal caudoputamen, zones of enhanced 5'-nucleotidase staining were restricted to calbindin-D28k-poor striosomes. Weak 5'-nucleotidase activity also emerged in the matrix. In striking contrast, in the mouse striatum, enhanced 5'-nucleotidase activity was preferentially associated with extrastriosomal tissue. Enzymatic reaction first appeared on embryonic day 18, and developed over the first postnatal week into a mosaic pattern in which the matrix was stained but the dopamine islands were unstained. The matrix staining itself was heterogeneous. After the second postnatal week, most of the caudoputamen was stained, and in adult mice only rostral striosomes expressed low 5'-nucleotidase activity. We conclude that in rats, 5'-nucleotidase represents one of the few substances that maintains a preferential dopamine island/striosome distribution during striatal development. In mice, 5'-nucleotidase activity is expressed preferentially in the matrix during development, and its compartmental pattern is gradually lost with maturation, except very rostrally. These findings do not suggest an instructive role of the enzyme in striatal compartment formation in either species, but do suggest the possibility that 5'-nucleotidase contributes to the differentiation of striatal compartments during development.
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PMID:Species-specific patterns of glycoprotein expression in the developing rodent caudoputamen: association of 5'-nucleotidase activity with dopamine islands and striosomes in rat, but with extrastriosomal matrix in mouse. 810 80

Previous studies have documented a highly compartmentalized and laminar organization of dopamine D2 receptors in human hippocampus, entorhinal and perirhinal cortices. These areas receive input from regions of polysensory association cortices of the superior and inferior temporal sulci that evidence functional modules identified by other techniques. We examined the isocortical regions of temporal lobe for an equally well-differentiated pattern of D2 receptor expression as observed in their paleocortical temporal lobe targets. Using quantitative autoradiography we identified an organization of three-dimensional bands of high concentrations of dopamine D2 receptors throughout the rostral-caudal extent of the normal human temporal cortex. In the coronal plane, these D2 receptor-enriched bands had a columnar appearance with the concentration of D2 receptors almost two-fold higher within the bands than in the immediately adjacent cortex. These D2 receptor-enriched bands had a distinct laminar appearance with a paucity of [125I]epidepride binding to D2 receptors over the granule cell layer and higher concentrations of D2 receptors in laminae III and V than in the immediately adjacent cortex. They had a consistent width (mean width of 2.83 +/- 0.62 mm) in the coronal plane, but had their long axes in the rostrocaudal plane (some were at least 2500 microns in length). Hence, they exist as three-dimensional D2 receptor-enriched and receptor-poor modules with their long axes in the rostrocaudal plane. Tyrosine hydroxylase-immunoreactive fibers were observed to cross orthogonally to the long axes of the D2 receptor enriched bands. Other monoamine receptors (beta-adrenergic, 5-hydroxytryptamine2), and markers for myelin (anti-myelin basic protein immunohistochemistry), glia (5'-nucleotidase), and energy metabolism (cytochrome oxidase) showed a laminar organization but failed to demarcate the D2 receptor-enriched bands. The majority of these D2 receptor-enriched bands were observed in the lateral and inferior aspects of the superior temporal gyrus, less frequently on the lateral surface of the inferior temporal gyrus and the parahippocampal cortices (Brodmann's area 22, 42 and 20, 21, 37). They were absent from primary auditory cortex (Brodmann's 41). The present study is the first known observation of a modular organization of synaptic elements, identified by D2 receptors, in non-primary sensory cortices of any species. The dopamine D2 receptor-enriched bands were found in regions previously identified as having functional modules that underlie feature extraction. Hence, D2 receptor-enriched and receptor-poor modules may provide a mechanism for functional regulation of compartments within these regions by dopamine.
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PMID:Dopamine D2 receptors are organized in bands in normal human temporal cortex. 886 95