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At least 613 records · Page 34Linked to original sources

PubMed1994

Neural sites of the human colon colocalize nitric oxide synthase-related NADPH diaphorase activity and neuropeptide Y.

BACKGROUND/AIMS: Nitric oxide and neuropeptide Y (NPY) exert similar biological actions in the mammalian intestine including modulation of food intake, blood flow, motility, and secretion. In addition, these substances coexist in submucosal secretomotor neurons of the rodent intestine. The aim of this study was to determine the relative disposition of elements displaying NPY immunoreactivity and NO synthase-related nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase activity in the nerve networks of the human infant colon. METHODS: Transverse and longitudinal sections, treated for immunohistofluorescent detection of NPY and then processed for NO synthase-related NADPH diaphorase histochemistry, were examined. RESULTS: Neural elements containing NPY immunoreactivity and NO synthase-related activity were identified in the external muscle layers, myenteric plexus, and all nerve layers of the submucosa, including Henle's plexus, the intermediate nerve layer, and Meissner's plexus. Perivascular NPY-immunoreactive nerve fibers did not contain NO synthase activity. There were no nitrergic perivascular nerve fibers. NPY-immunoreactive endocrine cells in the mucosa did not display NO synthase-related activity. CONCLUSIONS: These findings provide anatomical data indicating that NPY immunoreactivity and NO synthase-related activity are extensively colocalized in all layers of the human infant gut wall.

Amino Acid Oxidoreductases↗

PubMed1988

Immunocytochemical evidence for the colocalization of neurotensin/xenopsin- and gastrin/caerulein-immunoreactive substances in Xenopus laevis gastrointestinal tract.

Distribution and association of neurotensin (NT)- and xenopsin (XP)-like peptides were investigated using immunocytochemical techniques in the amphibian gut. Antisera against both groups of peptides showed an identical distribution pattern of NT- and XP-positive cells in Xenopus laevis gastrointestinal tract. Immunolabeling of consecutive semithin sections revealed the coexistence of NT- and XP-like substances within cells of the stomach and small intestine. Recent reports of the colocalization of XP-like material with gastrin in mammalian G cells led us to study the association of NT/XP-like peptides with members of the gastrin/cholecystokinin (CCK)/caerulein (G/C) family in amphibians. The data obtained from immunolabeling serial sections with NT/XP-specific and G/C-specific antisera show that in some intestine NT/XP- and G/C-like peptides do exist in the same cells. In the stomach, however, G/C-like material is confined to endocrine cells of the antral region, while NT/XP-like substances occur in distinct cells accumulating in cardial glands but absent in the pyloric glands. Our findings thus indicate that in amphibian gastrointestinal tract there is some association between the regulatory peptide families NT/XP and G/C, similar to mammals. The regional distribution of both hormone families, however, is different from that in mammals.

Animals↗

PubMed1992

Evidence for the colocalization of gastrin/CCK- and PYY/PP-immunoreactive substances in the small intestine of the lizard Podarcis hispanica: immunocytochemical and ultrastructural study.

Peptide tyrosine tyrosine/pancreatic polypeptide (PYY/PP)- and C-terminal gastrin/cholecystokinin (G/CCK)-immunoreactive cells were investigated in the intestine of the lizard Podarcis hispanica, using immunocytochemistry with light and electron microscopy. Immunolabeling of consecutive semithin sections revealed coexistence of PYY/PP- and C-terminal G/CCK-like substances in some cells, while in others only PYY/PP or G/CCK immunoreactivity was found. Appropriate absorption controls excluded cross-reactivity between the antisera used. Ultrastructurally G/CCK+, PYY/PP+ cells were similar to G/CCK+, PYY/PP- cells but different from PYY/PP+, G/CCK- cells. Although virtually nothing is known concerning the physiological effects of these peptides in reptiles, their colocalization in the same cells in the intestine of Podarcis hispanica suggests a close relationship between them in the regulation of the digestive process.

Amino Acid Sequence↗

PubMed1987

Prelesional events in atherogenesis. Colocalization of apolipoprotein B, unesterified cholesterol and extracellular phospholipid liposomes in the aorta of hyperlipidemic rabbit.

The appearance and accumulation of apolipoprotein B and unesterified cholesterol in the lesion-prone areas of the aorta in rabbits with diet-induced hyperlipidemia were investigated by histo-, and cytochemical techniques. Apolipoprotein B was detected by an indirect immunoperoxidase procedure both in the light and electron microscopy. Unesterified cholesterol was revealed using filipin and tomatine as specific probes. In the prelesional stages of atherogenesis, before the appearance of any structurally detectable lesions, as demonstrated by bright-field and fluorescence microscopy, apolipoprotein B and free cholesterol accumulated progressively in the extracellular matrix of the subendothelial space. At ultrastructural level, extracellular phospholipid liposomes, unesterified cholesterol and apolipoprotein B concomitantly appeared and accumulated focally in the same areas. Apolipoprotein B was preferentially located on the outer surface of the free cholesterol-containing phospholipid lamellae of the extracellular liposomes. In the lesional stages leading to fatty streak formation, the extracellular liposomes, apolipoprotein B and unesterified cholesterol had also topographically a superimposed localization pattern. Intracellular apolipoprotein B and unesterified cholesterol were also colocalized in some intimal lipid-laden cells. In the prelesional stages of hyperlipidemia the prevalent localization of apolipoprotein B around individual unesterified cholesterol-rich extracellular phospholipid liposomes, progressively accumulating in the subendothelial space, suggests their possible origin from serum-derived lipoproteins.

Animals↗

PubMed1992

Cocaine's colocalized effects on synaptic serotonin and dopamine in ventral tegmentum in a reinforcement paradigm.

The effect of subcutaneous (SC) cocaine (20 mg/kg) on synaptic concentrations of the biogenic amines, dopamine (DA), and serotonin (5-HT) in Ventral Tegmental Area, (VTA-[A10]) was studied in freely moving and behaving rats (rattus norvegicus) with in vivo voltammetry (in vivo electrochemistry). The actual detection of the biogenic amines was on-line and within a temporal resolution of seconds. Simultaneously, the psychostimulant behavior induced by cocaine was studied by infrared photocell beam detection. The results show that cocaine concurrently and significantly increased synaptic concentrations of DA (p less than 0.0001) and 5-HT (p less than 0.004) in VTA. Serotonin changes were accompanied by a notable oscillatory pattern. Importantly, DA and 5-HT changes in VTA were significantly and positively correlated (p less than 0.01). Moreover, psychostimulant behaviors induced by cocaine were significantly increased over control values (p less than 0.0001). Psychostimulant behaviors were significantly correlated with concurrently changing synaptic concentrations of DA (p less than 0.01) and also with 5-HT to a lesser degree. Additionally, behavioral data indicate that cocaine may exhibit an anxiolytic effect during acute administration because agoraphobic behavior, as shown by increased central ambulatory behavior, was dramatically reduced by cocaine. Summarily, the present findings show that cocaine increased synaptic concentrations of DA in VTA, an action that is correlated with cocaine-induced psychostimulant behavior. The DA-ergic effect appears to be tonically maintained. Furthermore, new findings demonstrate a colocalized, cocaine induced 5-HT-ergic effect in VTA, which keeps pace with cocaine-induced alterations in DA-ergic neurotransmission. Thus, 5-HT may be a relay or a gating mechanism for a DA reward signalling pathway for cocaine.

Animals↗

PubMed1987

Colocalization of calcium-dependent protease II and one of its substrates at sites of cell adhesion.

Adhesion plaques, specialized regions of the plasma membrane where a cell contacts its substratum, are dynamic structures. However, little is known about how the protein-protein interactions that occur at adhesion plaques are controlled. One mechanism by which a cell might modulate its associations with the substratum is by selective, regulated proteolysis of an adhesion plaque component. Here we show that the catalytic subunit of the calcium-dependent protease type II (CDP-II) is localized in adhesion plaques of several cell types (BS-C-1, EBTr, and MDBK). We have compared the susceptibility of the adhesion plaque constituents vinculin, talin, and alpha-actinin to calcium-dependent proteolysis in vitro and have found talin to be the preferred substrate for CDP-II. The colocalization of a calcium-requiring proteolytic enzyme and talin in adhesion plaques raises the possibility that calcium-dependent proteolytic activity provides a mechanism for regulating some aspect of adhesion plaque physiology and function via cleavage of talin.

Actinin↗

PubMed1990

Colocalized transmembrane determinants for ER degradation and subunit assembly explain the intracellular fate of TCR chains.

The intracellular fate of T cell antigen receptor (TCR) subunits (alpha beta gamma delta epsilon zeta 2) is determined by their assembly in the endoplasmic reticulum (ER). To study the structural bases for this tight correlation between assembly and intracellular fate, we sought to define the nature of determinants for both ER degradation and subunit assembly within the TCR-alpha chain. We found that a 9 amino acid transmembrane sequence of the TCR-alpha chain, containing 2 critical charged residues, was sufficient to cause ER degradation when placed in the context of the Tac antigen, used here as a reporter protein. CD3-delta assembled with chimeric proteins containing this short transmembrane sequence, and this assembly resulted in abrogation of targeting for ER degradation. Thus, the colocalization of determinants for ER degradation and sites of subunit interactions explains how the fate of some newly synthesized TCR chains can be decided on the basis of their assembly status.

Amino Acid Sequence↗

PubMed1995

CDC27Hs colocalizes with CDC16Hs to the centrosome and mitotic spindle and is essential for the metaphase to anaphase transition.

We have isolated cDNAs and raised antibodies corresponding to the human homologs of the S. cerevisiae CDC27 and CDC16 proteins, which are tetratrico peptide repeat (TPR)-containing proteins essential for mitosis in budding yeast. We find that the CDC27Hs and CDC16Hs proteins colocalize to the centrosome at all stages of the mammalian cell cycle, and to the mitotic spindle. Injection of affinity-purified anti-CDC27Hs antibodies into logarithmically growing HeLa cells causes a highly reproducible cell cycle arrest in metaphase with apparently normal spindle structure. We conclude that CDC27 and CDC16 are evolutionarily conserved components of the centrosome and mitotic spindle that control the onset of postmetaphase events during mitosis.

Anaphase↗

PubMedDate not supplied

Enkephalin and neuropeptide Y: two colocalized neuropeptides are independently regulated in primary cultures of bovine chromaffin cells.

We have found that Neuropeptide Y is colocalized with enkephalin in bovine adrenal chromaffin cells. The two peptides can be found in the same granules in those cells where they coexist. These cells correspond to the adrenergic subpopulation of chromaffin cells since they contain the epinephrine synthetic enzyme, phenylethanolamine N-methyltransferase. Despite their coexistence, production of the two peptides is independently regulated. Enkephalin levels are doubled after nicotinic depolarization (which increases enkephalin synthesis) or after treatment with reserpine (which increases enkephalin precursor processing). Neither of these treatments, acting by different mechanisms, has any effect on the levels of Neuropeptide Y.

Adrenal Glands↗

PubMed1990

Colocalization of peptides and a catecholamine-synthesizing enzyme in intramural neurones of the newborn guinea-pig urinary bladder in culture.

The patterns of colocalization of somatostatin (SOM), neuropeptide Y (NPY) and the catecholamine-synthesizing enzyme, dopamine beta-hydroxylase (DBH), were examined in intramural neurones in dissociated cell culture preparations from the detrusor muscle of the urinary bladder of the newborn guinea-pig using an elution-restaining immunocytochemical technique. Large numbers of the intramural neurones contained NPY-like (70-85% of the total neuronal population) and SOM-like (60-75%) immunoreactivities, in contrast to a small population (1-6%) of neurones containing immunoreactivity to DBH. Some neurones were immunoreactive to NPY (15-20%) and SOM (5-10%) alone, while 55-70% of the total neuronal population showed immunoreactivity to both NPY and SOM. NPY-like immunoreactive neuronal cell bodies that did not contain SOM were predominantly binucleate, whereas neuronal cell bodies immunoreactive to SOM alone were mainly mononucleate. Although not seen in every culture preparation, neuronal cell bodies containing both NPY-like and DBH-like immunoreactivities were also observed (less than 5% of the total neuronal population), and most, if not all, of these neuronal cell bodies were binucleate. SOM-like and DBH-like immunoreactivities were not seen in the same neuronal cell body throughout this study. These results show that intramural bladder neurones can be divided into distinct subpopulations based upon the coexistence of specific peptides and enzymes, and the possibility that they sustain local integrative and modulatory roles in bladder function is discussed.

Animals↗

PubMed1994

7B2 expression in intrapulmonary neuroepithelial bodies: immunocytochemical detection and colocalization with serotonin and calcitonin gene-related peptide.

In this study, the occurrence of 7B2, a highly conserved pituitary protein present in many neuroendocrine tissues and tumors, was investigated for the first time in the neuroendocrine cells (NEC) and neuroepithelial bodies (NEB) of hamster, rat and cat lung, as well as its colocalization with serotonin (5-HT) and calcitonin gene-related peptide (CGRP). Bouin fixed and wax embedded lung tissue was serially cut and immunoreactive sites for 7B2, 5-HT and CGRP were demonstrated on adjacent sections with polyclonal rabbit antibodies, using the streptavidin-biotin peroxidase method. 7B2 immunostained NEB were numerous in the intrapulmonary airways and the alveolar parenchyma, always representing a subpopulation of CGRP labelled NEB, but outnumbering those containing 5-HT. NEC, on the other hand, were only immunoreactive for CGRP and 5-HT. Our results suggest that mammalian NEB are storehouses of heterogenous bioactive substances, which may be important components in the development of bronchopulmonary tumors. Moreover, the ubiquitous presence of 7B2 in NEB supports the idea of a pre- and/or post-exocytotic role in the cellular secretory processes while the lack of 7B2 immunoreactivity in NEC might indicate a distinct function for each of both neuroendocrine cell types.

Animals↗

PubMed1991

Evidence for a colocalization of oxytocin mRNA and galanin in magnocellular hypothalamic neurons: a study combining in situ hybridization and immunohistochemistry.

The possible colocalization of oxytocin (OT) and galanin (GAL) was studied by combining, on the same cryostat sections, in situ hybridization (ISH) for OT mRNA with a tritiated oligonucleotide probe and immunohistochemistry (ICC) of GAL. Many cells were either labelled by ISH (OT mRNA containing cells), or by ICC (GAL containing cells). Moreover, some magnocellular neurons in the supraoptic and paraventricular nuclei were labelled for both OT mRNA and GAL. These results demonstrate that some magnocellular neurons of the rat hypothalamus contain both GAL and OT. This approach is suitable for studying the intracellular distribution of OT gene expression and mature GAL under different physiological or experimental conditions.

Animals↗

PubMed1993

Colocalization of muscarinic acetylcholine receptors and protein kinase C gamma in rat parietal cortex.

The present investigation analyzes the cellular distribution of muscarinic acetylcholine receptors (mAChRs) and the gamma isoform of protein kinase C (PKC) in the rat parietal cortex employing the monoclonal antibodies M35 and 36G9, respectively. Muscarinic cholinoceptive neurons were most present in layers 2, 3 and 5, whereas most PKC gamma-positive cells were found in layers 2, 5 and 6. Under normal, non-stimulated conditions, approximately 58% of all muscarinic cholinoceptive neurons were immunoreactive for PKC gamma. Conversely, nearly all PKC gamma-positive neurons were M35-immunoreactive. Although both pyramidal and nonpyramidal neurons express the two types of protein, the pyramidal cell type represents the vast majority. Of all cortical neurons, the large (15-25 microns in diameter) muscarinic cholinoceptive pyramidal neurons in layer 5 express the gamma isoform of PKC most abundantly and most frequently. Approximately 96% of these cells are immunoreactive for PKC gamma. Stimulation of mAChRs by the cholinergic agonist carbachol resulted in a pronounced increase in the intensity of 36G9 immunoreactivity, which may suggest that the mAChRs are functionally linked to the colocalized PKC gamma. No change was found in the number of 36G9-immunoreactive neurons. In contrast, the number of immunocytochemically detectable muscarinic cholinoceptive neurons increased by approximately 38% after carbachol stimulation. The high degree of codistribution in cortical neurons of both transduction proteins suggests a considerable cholinergic impact upon the regulation of PKC gamma, a candidate key enzyme in cortical learning and memory mechanisms.

Animals↗

PubMedDate not supplied

Corticotropin releasing factor-like immunoreactivity in sensory ganglia and capsaicin sensitive neurons of the rat central nervous system: colocalization with other neuropeptides.

Immunohistochemistry and radioimmunoassay (RIA) revealed that corticotropin releasing factor (CRF)-like immunoreactivity was found to be colocalized with substance P (SP)-, somatostatin (SST)- and leu-enkephalin (LENK)-like immunoreactivity in the dorsal root- and trigeminal ganglia, the dorsal horn of the spinal cord (laminae I and II), the substantia gelatinosa, and at the lateral border of the spinal nucleus and in the tractus spinalis of the trigeminal nerve. These peptides were also located in fast blue labeled cells of the trigeminal ganglion following injection of the dye into the spinal trigeminal area. This indicates that there are possible sensory projections of these peptides into the spinal trigeminal area. Capsaicin treatment of neonatal rats resulted in a marked decrease in the density of CRF-, SP-, VIP- and CCK-containing neurons in the above mentioned hindbrain areas, whereas SST- and LENK-immunoreactivity were not changed. RIA revealed that, compared to controls, CRF, SP and VIP concentrations in these areas were decreased in rats pretreated with capsaicin, while SST levels were increased; CCK and LENK levels were unchanged. It is concluded that the primary afferent neurons of the nucleus and tractus spinalis of the trigeminal nerve are richly endowed with a number of peptides some of which are sensitive to capsaicin action. The close anatomical proximity of these peptide containing neurons suggests the possibility of a coexistance of one or more of these substances.

Animals↗

PubMedDate not supplied

The colocalization of substance P- and somatostatin-like peptides in neurons of the entopeduncular nucleus of rats.

The colocalization of substance P-like and somatostatin-like immunoreactivity in cell bodies was investigated in the entopeduncular nucleus of rats by a double immunofluorescence method using species specific antibodies. Most of the substance P-like immunoreactive cells were also positive to somatostatin and mainly seen in the rostral to middle region of the entopeduncular nucleus. Therefore it is suggested that double-labeled neurons in the entopeduncular nucleus project to the lateral habenular nucleus which is involved in the limbic system, since the rostral portion of the entopeduncular nucleus has been shown to project to the lateral habenular nucleus.

Animals↗

PubMed1995

Cellular colocalization of diuretic peptides in locusts: a potent control mechanism.

Locust abdominal ganglia are shown to colocalize Locusta-diuretic peptide-, leucokinin I-, and lysine vasopressin-like immunoreactivity in posterior lateral neurosecretory cells. Extracts of abdominal ganglia were partially purified by RP-HPLC then dot immunoassay screened with the same antisera used for immunocytochemistry. Locusta-diuretic peptide-like immunoreactive material coeluted with synthetic Locusta-diuretic peptide, and leucokinin-like immunoreactive material coeluted with locustakinin. Lysine vasopressin-like material eluted in fractions that also showed Locusta-diuretic peptide and leucokinin I immunoreactivity. The diuretic activity of synthetic Locusta-diuretic peptide and locustakinin is demonstrated, and they are shown to act at least additively to promote Malpighian tubule fluid secretion. The immunoreactive neurosecretory cells are assumed to express at least these two peptides, and a model for promoting fluid secretion is proposed.

Abdomen↗

PubMed1994

Colocalization of atrial natriuretic factor and beta-endorphin in rat thymic macrophages.

Recent demonstration of immunoreactive (IR) atrial natriuretic factor (ANF) and beta-endorphin (beta-EP) in the thymus prompted a reexamination of the distribution and cellular localization of the two peptides within that tissue. Double labeling immunohistochemistry was carried out on gelatin-embedded cryostat thymic sections of adult male Sprague-Dawley rats. Cells stained positive with antiserum (S118), raised against rANF(1-28), were colocalized in > 95% of cases with immunofluorescent staining of IR-beta-EP(1-31). The cells were found sparsely distributed along the corticomedullary junction and in subcapsular regions. In 1- or 5-day monolayer cultures of adherent thymic cells, 15-20% of the cells stained positive for either IR-ANF or IR-beta-EP. Under these conditions, > 95% of IR-ANF or IR-beta-EP positive cells were also fluorescence stained for the rat macrophage marker ED-1. Thus, taken together with previous reports, our present findings suggest that, in the rat thymus, both ANF and beta-EP are produced by the same population of macrophages. To further investigate their presence in the thymus, the contents and molecular species of the two peptides were compared over the developmental period of the animal using well-characterized radioimmunoassays (RIA). Both peptides significantly increased their contents between day 2 and day 60. However, in terms of concentration, IR-ANF at day 2 was approximately 50% higher than day 16 and five times greater that at day 60; in comparison the concentration of IR-beta-EP remained relatively constant and the only significant difference from day 2 being a slight increase in the day 16 animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1996

NF-kappa B transcription factor subunits in rat brain: colocalization of p65 and alpha-MSH.

The subunit proteins p50 and p65 of the transcription factor NF-kappa B inhibitory protein were immunocytochemically identified and mapped in rat brain. The p65 subunit was localized to the cytoplasm of neurons in the lateral hypothalamus and colocalized with alpha-MSH in neurons identified as the alpha-2 component of the alpha-MSH system. The p50 subunit protein was distributed throughout the neocortex, basal ganglia, thalamic, and hypothalamic nuclei, and certain nuclei of the pons and medulla. The I-kappa B protein, which is necessary for the cytoplasmic sequestration of the NF-kappa B transcription factor complex, was identified specifically in regions of limbic, hypothalamic, and autonomic nuclei.

Animals↗