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At least 595 records · Page 33Linked to original sources
PubMed1995

Colocalization of Rh polypeptides and the aminophospholipid transporter in dilauroylphosphatidylcholine-induced erythrocyte vesicles.

Cytoskeleton-free vesicles released from human red blood cells (RBC) transport exogenously supplied aminophospholipid analogues from the vesicle's outer to inner leaflet at rates comparable to those of normal RBC (Beleznay et al. (1993) Biochemistry 32, 3146-3152). Because polypeptides associated with the Rh blood group system have been implicated in the transbilayer movement of phosphatidylserine (PS), we investigated the relationship and co-localization of the aminophospholipid translocase and Rh in dilauroylphosphatidylcholine-induced RBC vesicles. The transbilayer movement of fluorescent (NBD-PS) and photoactivatable (125I-N3-PS) PS in RBC vesicles was ATP-and temperature-dependent. Inhibition of PS transport by sulfhydryl reagents could be accomplished by direct vesicle treatment or by treating RBC before vesiculation. In the case of diamide- and pyridyldithioethylamine-mediated inhibition, NBD-PS transport could be restored by reduction with dithiothreitol, indicating that the movement of the PS transporter into the emerging vesicle was independent of the oxidative status of membrane sulfhydryls. The presence of Rh polypeptides in the vesicles was verified by direct immunoprecipitation of isotopically-labeled Rh and semi-quantified by antibody adsorption assays. Similar to the movement of the PS transporter, localization of Rh polypeptides in the vesicle membrane was independent of the red cell's oxidative status. These results show that the PS translocase and Rh-related proteins colocalize in RBC vesicles suggesting that these proteins may be members of a multicomponent complex that plays a role in lipid movement and the generation of membrane lipid asymmetry.

Biological Transport↗
PubMed1985

Colocalization of dynorphin-A(1-17) and dynorphin-A(1-8) within some perikarya of rat duodenum: immunohistochemical evidence for the presence of two separate dynorphinergic systems.

Adjacent serial sections through the rat duodenum were alternately stained for immunofluorescence microscopic studies with specific anti-sera directed to the opioid peptides dynorphin-A(1-17) and dynorphin-A(1-8), respectively. This resulted in the evidence that two separate dynorphinergic neuron populations are present there: intramural neurons, revealing a colocalization of dynorphin-A(1-17) and dynorphin-A(1-8), were round, contained a large and round nucleus and were lying sporadically in the longitudinal muscle layer as well as bulb-shaped neurons expressing only a dynorphin-A(1-8) immunoreactivity. The latter were recognized abundantly in the myenteric plexus. Myenteric plexus nerve fibres and terminals were immunoreactive for dynorphin-A(1-8), but not for dynorphin-A(1-17). Dynorphin-A(1-8) immunostained nerve terminals formed close contacts with large non-dynorphinergic myenteric plexus perikarya. These findings might indicate that dynorphin-A(1-8) is processed directly from its prodynorphin ('preproenkephalin B') precursor within myenteric plexus perikarya and indirectly via dynorphin-A(1-17) within intramural perikarya, indicating the presence of two separate dynorphinergic systems in the rat duodenum.

Animals↗
PubMed1989

A mechanism for the involvement of colocalized neuropeptides in the actions of antipsychotic drugs.

Evidence has accumulated to implicate neuropeptides localized within midbrain dopamine neurons (cholecystokinin, neurotensin, acetylcholinesterase) in synaptic transmission, mental disease, and pharmacotherapy. We suggest a means by which antipsychotic drugs alter the dynamics between dopamine and colocalized peptides: the intrinsic ability of these agents to stimulate dopamine neuronal activity while blocking dopamine receptors modulates the ratio of catecholaminergic to peptidergic transmission within the mesotelencephalic system. Imbalances of peptide and dopamine cotransmission and their modulation by neuroleptics may be relevant to the pathogenesis and pharmacotherapy of schizophrenia.

Animals↗
PubMed1985

alpha-Melanotropin, beta-endorphin and adrenocorticotropin-like immunoreactivities are colocalized within duodenal myenteric plexus perikarya.

The opioid peptide beta-endorphin co-exists with alpha-melanotropin and adrenocorticotropin within myenteric neuronal cell bodies of the rat duodenum. Adjacent serial sections through the myenteric and submucous plexus have been stained alternately with antisera directed against alpha-melanotropin, beta-endorphin and adrenocorticotropin. This resulted in nearly superimposable immunofluorescences for the 3 peptides within neuronal cell bodies of the myenteric plexus. An alpha-melanotropin staining was always linked by an immunofluorescence for beta-endorphin, adrenocorticotropin and vice versa. These staining patterns were not seen in the submucous plexus. Some tangentially cut nerve fibers running through the longitudinal muscle layer revealed a coexistence of adrenocorticotropin and alpha-melanotropin. The colocalization of beta-endorphin, alpha-melanotropin and adrenocorticotropin within the same perikarya may reflect a physiological role for the 3 peptides in the nervous system of the rat duodenum.

Adrenocorticotropic Hormone↗
PubMed1987

Some transforming growth factor-alpha connections and their colocalization with enkephalin in the rat central nervous system.

Transforming growth factor alpha (TGF alpha) has been immunocytochemically localized in neuronal perikarya throughout the adult rat central nervous system (CNS). In order to determine if any TGF alpha-immunoreactive (TGF alpha-I) cell bodies have long axonal projections, indirect immunofluorescence was used in combination with injections of the fluorescent retrograde tracer, Fluoro-Gold (FG). Both TGF alpha-I and retrogradely transported FG were found within the same neurons in the interpeduncular nucleus (IPN) after bilateral FG injections in the dorsal tegmental nucleus (DTg). Neurons that contain both TGF alpha-I and FG were also found in the raphe magnus, raphe obscurus, raphe pallidus and the gigantocellularis reticular nuclei after FG injections in the upper thoracic spinal cord. Cell bodies double-labeled with TGF alpha-I and FG were found in the dorsal parabrachial nucleus (DPB) following FG injections in the central nucleus of the amygdala (Ce). In addition, Leu-enkephalin immunoreactivity (L-ENK-I) was colocalized with TGF alpha-I in the same projection neurons after the injections described above. These results suggest that cells that contain TGF and the opioid peptide, L-ENK, have long projections in the rat CNS, and that, due to their co-localization within the same neurons, they may exert their effects concomitantly.

Animals↗
PubMed1988

Colocalization of substance P and gamma-aminobutyric acid in amacrine cells of the cat retina.

Substance P and gamma-aminobutyric acid (GABA) were colocalized by immunocytochemistry in two subpopulations of amacrine cells in the cat retina. All of the cells which stained for substance P also showed GABA reactivity. However, there were many GABA-immunoreactive cells which did not stain for substance P. The presence of neuropeptides provides a basis for additional neurochemical characterization of the multiple populations of GABA immunoreactive cells.

Animals↗
PubMed1989

Parvalbumin is highly colocalized with calbindin D28k and rarely with calcitonin gene-related peptide in dorsal root ganglia neurons of rat.

Sections of lumbar dorsal root ganglia from rat were analyzed by immunohistochemical techniques to determine the size distribution and numbers of cells containing parvalbumin and calbindin D28k and to establish their coexistence relationships with each other and with cells containing calcitonin gene-related peptide (CGRP). The proportion of ganglia cells containing parvalbumin and calbindin D28k was 14% and 22%, respectively. The majority of cells immunoreactive for these proteins were of the large A type. Parvalbumin was colocalized almost completely (greater than 99%) with with calbindin D28k and minimally (less than 1%) with CGRP. Only 9% of the calbindin D28k-positive cells were immunoreactive for CGRP.

Animals↗
PubMed1991

Colocalization of muscarinic and nicotinic receptors in cholinoceptive neurons of the suprachiasmatic region in young and aged rats.

In the present study muscarinic and nicotinic cholinergic receptors in the SCN region were demonstrated and analyzed, employing monoclonal antibodies to purified muscarinic and nicotinic cholinergic receptor proteins. A near-total colocalization of the two acetylcholine receptor subclasses in cholinoceptive neurons of the SCN area was found. The antibodies applied to aging rat brain (at 30-34 months) revealed a clear decrease in immunoreactivity in senescence albeit with a high level of individual variability. Furthermore, in 8 out of 10 aged animals examined a considerable increase of astrocytes possessing muscarinic cholinergic receptors was observed.

Aging↗
PubMed1992

Colocalization of peptide- and tyrosine hydroxylase-like immunoreactivities with Fos-immunoreactive neurons in rat central amygdaloid nucleus after immobilization stress.

The central amygdaloid nucleus (ACe) is part of the amygdaloid body, and it has been shown to participate in several stress related reactions. The ACe is densely innervated by tyrosine hydroxylase- (TH), corticotropin releasing factor- (CRF), calcitonin gene-related peptide- (CGRP), neurotensin- (NT), somatostatin- (SOM), enkephalin- (ENK), substance P- (SP), vasoactive intestinal polypeptide- (VIP) and cholecystokinin- (CCK) immunoreactive (IR) nerve terminals. In addition, the ACe contains numerous CRF-, NT-, SOM-, ENK- and SP-IR perikarya. In previous studies it has been shown that stress stimulates the expression of the immediate early gene c-fos in the ACe. The aim of this study was to demonstrate the colocalization of the Fos-IR neurons with the peptide- and TH-IR structures using an immunocytochemical double staining technique. In intact animals the ACe contained only a few Fos-IR neurons. After immobilization stress about 100 Fos-IR neurons were seen per section. They were mainly located in the area, which was enriched by peptide- and TH-IR nerve terminals. The close contacts observed between the Fos-IR neurons and the peptide- and TH-IR nerve endings suggest that the Fos-IR neurons were innervated by these nerve terminals. Furthermore, several NT-, ENK-, SOM- and CRF-IR neurons were observed and the vast majority of these cells exhibited Fos-like immunoreactivity. These results suggest that stress enhances the synaptic activity of the ACe, which stimulates the expression of c-fos. Subsequently, Fos may regulate the expression of the NT, ENK, SOM and CRF genes and thus affect the peptidergic efferents from the ACe.

Amygdala↗
PubMed1992

Immunocytochemical localization of parvalbumin- and neurofilament triplet protein immunoreactivity in the cat retina: colocalization in a subpopulation of AII amacrine cells.

Using antibodies against parvalbumin and neurofilament triplet protein, colocalization of these two neuronal markers was revealed in all of type A horizontal cells and alpha ganglion cells and in a small number of AII amacrine cells of the cat retina. Besides the double-labeled neurons, parvalbumin alone was present in type B horizontal cells, in small numbers of starburst- and A13-like amacrine cells and in the somata of unidentified ganglion cells. The processes of the double- or single-labeled amacrine cells did not have a continuous retinal cover. Although the parvalbumin- and neurofilament-immunolabeled amacrine cells belonged to groups of neurons with well-defined cell morphologies, their neurochemical features differed from other AII, starburst and A13 amacrine cells. The presence of these cells may be due to an accidental expression of an unusual combination of neurochemical features during retinal development. It is also possible that these cells support the functioning of ganglion cells with rarely occurring complex receptive fields.

Animals↗
PubMed1993

Colocalization of D1 and D2 dopamine receptor mRNAs in striatal neurons.

There is evidence that D1 and D2 dopamine receptor subtypes coexist at the cellular level in the striatum and act synergistically to mediate the effects of dopamine. Other data suggest that these receptor subtypes are largely segregated in different striatal projection pathways. We used in situ hybridization in serial adjacent 4 microns sections to determine the extent of colocalization of D1 and D2 receptor mRNAs in rat striatal neurons. Cellular localization of D1 and D2 receptor mRNA was performed on section pairs that were hybridized with 35S-labeled cDNA or oligonucleotide probes directed against non-homologous regions of D1 and D2 receptor mRNAs. We found that 26-27% of striatal cells containing one receptor subtype also contained the other subtype. Thus, although D1 and D2 receptors are segregated in the majority of striatal neurons, a substantial number of striatal neurons coexpress both dopamine receptor mRNA subtypes. Our findings provide anatomic support for many of the functional interactions that have been described for D1 and D2 receptors.

Animals↗
PubMed1994

Nitric oxide synthase immunoreactivity colocalized with NADPH-diaphorase histochemistry in monkey cerebral cortex.

The distributions of reduced nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) and nitric oxide synthase (NOS) containing neurons and the extent of NADPH-d and NOS colocalization have been analyzed by histochemical and immunocytochemical techniques in the neocortex of Macaca fuscata monkeys. NADPH-d positive cells were consistently also NOS positive and presented a relatively uniform distribution from area to area, but area-specific differences were observed in the pattern of distribution of fiber plexuses.

Amino Acid Oxidoreductases↗
PubMed1995

Colocalization of fructose-1,6-bisphosphatase and glial fibrillary acidic protein in rat brain.

Immunofluorescence studies of rat brain sections demonstrated an exclusive colocalization of the gluconeogenic key enzyme fructose-1,6-bisphosphatase (FBPase) with the astroglial marker glial fibrillary acidic protein, indicating FBPase in brain as an astrocyte-specific enzyme. This conclusion was supported by the presence of FBPase activity in astroglia-rich but not neuron-rich primary cultures derived from rat brain.

Animals↗
PubMed1995

Colocalization of glycine and GABA in synapses on spinomedullary neurons.

Spinomedullary neurons of the postsynaptic dorsal column pathway in adult cats were retrogradely labelled with horseradish peroxidase. Postembedding immunogold reactions were performed with antisera which recognise GABA or glycine to determine if synaptic boutons in contact with these neurons contain both transmitters. Analysis of series of ultrathin sections revealed that synaptic profiles with strong immunogold reactions for GABA usually also displayed strong immunogold reactions for glycine. Pre-embedding immunocytochemistry was performed on sections containing labelled cells with a monoclonal antibody which recognises the glycine receptor-associated protein, gephyrin. Many synapses onto postsynaptic dorsal column neurons were associated with gephyrin-like immunoreactivity and these typically contained irregularly shaped vesicles. Immunogold reactions showed that synaptic profiles apposed to gephyrin-immunoreactive junctions contained GABA and glycine. The evidence suggests that glycine is a neurotransmitter at synapses on spinomedullary neurons and that it is colocalized with GABA.

Animals↗
PubMed1995

Cellular colocalization of Fos and neuropeptide Y in the intergeniculate leaflet after nonphotic phase-shifting events.

Nonphotic and photic stimuli that phase shift circadian rhythms were presented to hamsters, Mesocricetus auratus. The nonphotic stimulus was a 3-h pulse of novelty-induced wheel running starting at circadian time 4-5. The photic stimulus used was a 0.5 h light pulse starting at circadian time 18. Double immunocytochemistry was used to determine the neurochemical phenotype of cells in the intergeniculate leaflet that were activated by these stimuli. Both the nonphotic and the photic phase-shifting stimuli induced the expression of c-fos in the intergeniculate leaflet compared to unstimulated controls. However, after nonphotic stimulation, Fos-like immunoreactivity was common in neurons that also were NPY positive. Such colocalization of Fos and NPY after photic stimuli was rare. These findings suggest that the NPY pathway from the intergeniculate leaflet to the suprachiasmatic nucleus carries information about nonphotic events.

Animals↗
PubMed1991

Colocalization of N-CAM and N-cadherin in avian skeletal myoblasts.

The cell-cell adhesion molecules, N-CAM and N-cadherin, have been shown previously to mediate myoblast interaction during cell fusion accompanying skeletal myogenesis. To study the localization of both molecules in fusion-competent myoblasts, we used antigen-specific primary antibodies and a double-labeling preembedding immuno-electron microscopy technique. Ultrastructural observations and quantitative analysis of the results reveal that N-CAM and N-cadherin frequently colocalize in clusters on the myoblast plasma membrane. The data provide morphological evidence that the two adhesion glycoproteins cooperate in mediating myoblast interaction during myoblast fusion.

Animals↗
PubMed1994

Colocalization of neuropeptides with calbindin D28k and NADPH diaphorase in the enteric nerve plexuses of normal human ileum.

BACKGROUND/AIMS: The chemical coding of enteric neurons differs significantly among species. In the present study, the innervation of normal human ileum was characterized with respect to its chemical coding. METHODS: The submucosa was subdivided into zones 1-3 based on its thickness and distribution of ganglia. The neuropeptides, calbindin D28k, and protein gene product 9.5 were identified by immunocytochemistry. Nitric oxide production was identified by nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry. RESULTS: Protein gene product 9.5 staining indicated that cell bodies of the submucosa could be subdivided into zones 1-3. Two major groups of submucosal cell bodies contained either substance P/somatostatin/calcitonin gene-related peptide or vasoactive intestinal peptide/neuropeptide Y/calbindin D28k. Gastrin-releasing peptide-containing cell bodies also colocalized with a subgroup of somatostatin cell bodies. No galanin, met-enkephalin, or NADPH diaphorase-positive cell bodies were present. In the myenteric plexus, the two major groups of cell bodies contained either calbindin or NADPH diaphorase. A proportion of the latter group costained with vasoactive intestinal peptide and met-enkephalin. Cell bodies containing substance P, somatostatin, and calcitonin gene-related peptide were present, forming three different subgroups. CONCLUSIONS: Of the species investigated to date, the chemical coding of human ileal cell bodies most closely resembles that of the rat.

Calbindin 1↗