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M Tohyama

Publications and source records attributed to M Tohyama.

At least 343 records · Page 19Linked to original sources
PubMed1989

A monoclonal antibody against COOH-terminal peptide of human liver manganese superoxide dismutase.

Three stable hybridoma cell lines producing monoclonal antibodies specific for human liver manganese superoxide dismutase were established, and one monoclonal antibody, PG 11, was chosen for immunochemical studies. Immunoblotting demonstrated that the monoclonal antibody binds exclusively to the manganese superoxide dismutase. Immunohistochemical studies indicated that the enzyme is localized in the matrix of human liver mitochondria. To localize antibody-binding epitope, synthetic peptides of the NH2-terminal (residues 1-16) and COOH-terminal (residues 182-189, 190-196, and 182-196) parts of the enzyme were synthesized, and then their effects on the binding were studied using an enzyme-linked immunosorbent assay method. All of the above COOH-terminal peptides inhibited the binding whereas the NH2-terminal ones did not, indicating that PG 11 recognizes several peptides of COOH termini of manganese superoxide dismutase. This is the first report of monoclonal antibodies against human manganese superoxide dismutase with a distinct epitope and of the immunocytochemical demonstration of manganese superoxide dismutase.

Animals↗
PubMed1989

Immunohistochemical distribution of somatostatin in the infant hypothalamus.

Somatostatin (SS)-containing neurons were mapped in the normal infant hypothalamus with immunohistochemistry, using the peroxidase anti-peroxidase technique. Neurons displaying SS immunoreactivity show a widespread distribution throughout the hypothalamic region. Principal SS-immunoreactive like (SS-IL) perikarya are located in the paraventricular, infundibular and posterior nuclei and in the preoptic region. High SS innervation is also found in the ventromedial and in the lateral mammillary nuclei, and in the median eminence. In general this distribution of SS-IL agrees well with that reported for rat. Compared to the immunohistochemical distribution of SS in human adult hypothalamus, this mapping in the infant hypothalamus is grossly similar. However some differences may be underlined: the presence of a moderately dense group of SS-IL perikarya in the tuberal and posterior nuclei, and a dense innervation of the ventromedial nucleus and in the median eminence. This first detailed distribution of SS immunoreactivity in infant hypothalamus can provide basic knowledge for further studies of infant neuropathology.

Humans↗
PubMed1989

Distribution of neuropeptidelike immunoreactivities in the guinea pig olfactory bulb.

The distribution of neuropeptidelike immunoreactivities in the adult guinea pig olfactory bulb was studied immunohistochemically with antisera raised against neurotensin (NT), substance P (SP), methionine-enkephalin-Arg6-Gly7-Leu8 (ENK), somatostatin (SOM), neuropeptide Y (NPY), and cholecystokinin-8 (CCK). In the main olfactory bulb, NT-like immunoreactive (NT-IR) neurons were found among periglomerular cells. In addition, a few periglomerular cells showed ENK-like immunoreactivity. Granule cells displaying SP- or ENK-like immunoreactivities and short axon cells with SOM- or NPY-like immunoreactivities were observed in the deeper half of the granule cell layer. SOM-IR short axon cells were also seen in the external plexiform layer. Dense NT- or NPY-IR fibers were distributed in superficial lamina of the granule cell layer, and sparse SP- or CCK-IR fibers were found in the glomerular layer. In the accessory olfactory bulb, some mitral, periglomerular, and granule cells showed NT-like immunoreactivity. SP- or ENK-IR granule cells were also observed. These results are discussed in relation to laminar organization of the olfactory bulb. The most characteristic features of peptide distribution in guinea pigs, as compared with that of rats in previous studies, were the relative abundance of NT-IR structures and the lack of SP- and CCK-IR juxtaglomerular and tufted cells.

Animals↗
PubMed1989

The organization of the rat lateral geniculate body by immunohistochemical analysis of neuroactive substances.

The organization of neuroactive substances in the rat lateral geniculate body (LGB) was studied with available immunohistochemical stainings. In the dorsal lateral geniculate nucleus (DLG), there existed only gamma-aminobutyric acid (GABA)-like immunoreactive neurons. Immunoreactive fiber plexuses for substance P (SP), cholecystokinin-8 (CCK) and vasoactive intestinal polypeptide (VIP) were present in the lateral margin of the DLG, just beneath the optic tract. There were immunoreactive neurons and fibers for GABA, SP, leucine-enkephalin (ENK) and neuropeptide Y (NPY) in the intergeniculate leaflet (IGL). ENK-, NPY- and SP-like immunoreactive neurons in the IGL were mainly medium-sized, and bipolar or spindle-shaped with a few dendrites oriented dorsoventrally. In the IGL, use of double-labeled immunofluorescence demonstrated that a few neurons exhibited both ENK- and SP-like immunoreactivities, and a few neurons had both GABA- and ENK-like immunoreactivities. Although the morphology of ENK-like immunoreactive neurons resembled to NPY-like immunoreactive neurons, both neurons were clearly different neurons. Many GABA-, ENK- and SP-like immunoreactive neurons and fibers were found in the ventral lateral geniculate nucleus (VLG). These immunoreactive neurons were mainly medium-sized, and bipolar in shape, while a few immunoreactive neurons were of multipolar shape. Neurons containing ENK and fibers containing SP mainly existed in the lateral half of the parvocellular part and in the medial half of magnocellular part of the VLG. In this region, about one-third of the GABA-like immunoreactive neurons contained ENK-like immunoreactivity. Many SP neurons mainly existed in the medial half of the parvocellular part of the VLG. CCK- and VIP-like immunoreactive fibers were present in the lateral half of the magnocellular part of the VLG. Immunoreactive fibers for calcitonin gene-related peptide, corticotropin-releasing factor, neurotensin and tyrosine hydroxylase were disseminated throughout the LGB. The subdivisions of the LGB were discussed, based upon the distribution of neuroactive substances.

Animals↗
PubMed1989

Laminar and segregated distribution of immunoreactivities for some neuropeptides and adenosine deaminase in the superior colliculus of the rat.

The distribution and morphology of adenosine deaminase, substance P, leucine-enkephalin, corticotropin-releasing factor, and calcitonin gene-related peptidelike immunoreactive cells and fibers throughout the superior colliculus of the rat were examined by means of the unlabelled-antibody peroxidase-antiperoxidase method. Adenosine deaminase immunoreactive cells were found in the stratum opticum and lower stratum griseum superficiale; substance P immunoreactive cells were localized to the upper stratum griseum superficiale, and calcitonin gene-related peptide immunolabelled neurons were situated in deeper strata. Substance P, leucine-enkephalin, and calcitonin gene-related peptide immunoreactive fibers were distributed similarly in their lamination and in their patchlike organization. Corticotropin-releasing factor immunoreactive fibers were observed evenly throughout all the strata and were fewer in the stratum griseum superficiale. These findings suggest that, as in afferent modules and segregated efferents of the mammalian superior colliculus, the cells and fibers containing neuroactive substances and neuroactive substance-related enzymes also show a segregated and laminar distribution.

Adenosine Deaminase↗
PubMed1989

Presence of catecholaminergic axon-terminals containing beta-adrenergic receptor in the periventricular zone of the rat hypothalamus.

The present study, using a light microscopic double-immunofluorescence method, has revealed the presence of fibers containing both tyrosine hydroxylase- and beta-adrenergic receptor-like immunoreactivities in the rat hypothalamic periventricular zone. Subsequent immunoelectron microscopic analysis demonstrated that these belong to axon terminals. These findings suggest that presynaptic beta-adrenergic receptor is present in catecholaminergic terminals.

Animals↗
PubMed1989

Ontogeny of calcitonin gene-related peptide in the organ of Corti of the rat.

The ontogeny of calcitonin gene-related peptide (CGRP)-like immunoreactive (CGRPI) fibers in the rat cochlea was examined using immunocytochemistry. It was found that the CGRPI cochlear system developed markedly in the postnatal period; CGRPI fibers first appeared in the inner spiral bundle at postnatal day 8, then at the base of the outer hair cells, tunnel spiral bundle and tunnel radial fibers at postnatal day 19. The ontogenetical profile elucidated by this study suggests that CGRP has a role as a neuromodulator or neurotransmitter in this system.

Animals↗
PubMed1989

Adenosine deaminase containing fiber pathway from the superior colliculus to the lateral posterior nucleus of the rat.

Presence of a projection containing adenosine deaminase (ADA)-like immunoreactivity from the stratum opticum (SO) to the dorsomedial portion of the lateral posterior nucleus of the thalamus (LPN) of the rat was demonstrated using a method combining retrograde tracing by horseradish peroxidase (HRP) and immunohistochemistry for ADA. In the caudal two thirds of the LPN, a clearly delimited ADA-like immunoreactive fiber plexus was located. Injection of HRP into the lateral posterior nucleus labeled many neurons in the medial portion of the SO where medium-sized neurons with ADA immunoreactivity were concentrated. Simultaneous immunostaining showed that some of the HRP-labeled neurons are ADA-positive.

Adenosine Deaminase↗
PubMed1989

Cellular analysis of c-Ha-ras gene expression in rat liver after CCl4 administration.

Expression of the c-Ha-ras proto-oncogene is specifically enhanced during liver regeneration, in parallel with increased DNA replication, which suggests that c-Ha-ras may play a role in the control of regeneration. In this study, an in situ hybridization technique was applied for analysis of expression of the c-Ha-ras gene at the cellular level during liver regeneration induced by CCl4 administration. The in situ hybridization was compared with the observation for the p21c-Ha-ras protein, the corresponding protein of the c-Ha-ras gene, by immunohistochemistry. In normal rat liver, a few hepatocytes expressed the mRNAs and the corresponding proteins without any preferential localization. Zonal heterogeneity of c-Ha-ras gene expression first became evident at 12 hr after CCl4 administration, a higher number of gene products being detected in the pericentral zone than in the periportal zone. This heterogeneity became maximal at 24 hr after CCl4 administration. Zonal heterogeneity in the level of the p21c-Ha-ras protein paralleled that in the level of gene expression. Furthermore, both hepatocytes and nonparenchymal cells participated in expression of the c-Ha-ras gene during liver regeneration.

Animals↗
PubMed1989

Co-localization of adrenergic receptors and vitamin-D-dependent calcium-binding protein (calbindin) in the dopaminergic amacrine cells of the rat retina.

Using antisera against tyrosine hydroxylase (TH) and purified beta 2-adrenergic receptors (beta 2-AdR), we found that TH- and AdR-like immunoreactivities coexisted in large amacrine cells. These findings indicated an association between dopamine-containing amacrine cells and adrenergic amacrine cells. The present study also showed that amacrine cells with TH-like immunoreactivity have vitamin-D-dependent calcium-binding protein (calbindin, 27,000 kDa)-like immunoreactivity as well, suggesting that calbindin plays an important postsynaptic role in dopaminergic amacrine cells.

Animals↗
PubMed1989

Preproenkephalin gene expression in the rat spinal cord after noxious stimuli.

The trans-synaptically activated biosynthesis of the preproenkephalin (PPE) mRNA in the dorsal horn of the rat lumbar spinal cord was examined by an in situ hybridization histochemical technique. As a nociceptive stimulus, a small amount of formalin was injected into the right hindpaw, and quantitative and qualitative changes of PPE-mRNA expression were determined by emulsion autoradiography. Formalin injection was found to result in a significant increase in the number and signal intensity of neurons expressing PPE-mRNAs in the superficial and deep layers of the ipsilateral spinal dorsal horn. Expression of PPE-mRNA increased within 1 h after formalin injection in neurons of deep layers, but gradually for at least 24 h in neurons in the superficial layers. These results at the level of the spinal cord showed that differential responses of PPE neurons related to the pain sensation occurred trans-synaptically after nociceptive stimulation applied to the periphery.

Animals↗
PubMed1989

Prepro-VIP and preprotachykinin mRNAs in the rat dorsal root ganglion cells following peripheral axotomy.

Using in situ hybridization histochemistry, we examined the expression of prepro-vasoactive intestinal polypeptide (VIP) mRNAs and preprotachykinin (PPT) mRNAs which coded for substance P (SP) in the rat dorsal root ganglion (DRG) following spinal nerve transection. VIP mRNAs increased dramatically in the DRG neurons after transection of the peripheral branch of the spinal nerve (sciatic nerve), whereas PPT mRNAs showed a gradual decrease for a few weeks. Dorsal rhizotomy or axotomy of the central branch of DRG cells had little influence on VIP-mRNAs and no effect on PPT mRNA expression. These results demonstrated an activation of VIP biosynthesis in the DRG neurons due to axotomy of the peripheral branch, which was opposite to the reaction of PPT mRNA to the same treatment.

Animals↗
PubMed1989

Ultrastructural investigation of substance P-, leucine-enkephalin- and 5-hydroxytryptamine-like immunoreactive terminals in the area of cremaster motoneurons of the male rat.

Studies were made on whether substance P-, leucine-enkephalin- and 5-hydroxytryptamine (serotonin)-like immunoreactive fibers exert a direct influence on the cremaster motoneurons of the male rat by immunocytochemistry combined with retrograde tracing at the light- and electron-microscopic levels. Horseradish peroxidase was used as a retrograde tracer. Two days after injection of horseradish peroxidase into the genitofemoral nerves, its accumulation in the cremaster motoneurons was demonstrated by the diaminobenzidine-nickel method. On immunocytochemical examination of the same sections immunoreactive end-products were detected by the peroxidase-antiperoxidase method. Two different kinds of reaction products were distinguishable at both the light- and electron-microscopical levels. The horseradish peroxidase-labeled cremaster motoneurons at the L1 and L2 levels of the spinal cord were surrounded by abundant immunoreactive terminals. Examination at the ultrastructural level showed that substance P-like immunoreactive terminals formed synaptic contacts almost exclusively with the proximal dendrites of these horseradish peroxidase-labeled cremaster motoneurons. On the other hand, in the leucine-enkephalin- and serotonin-like boutons, significant numbers of axosomatic contacts with horseradish peroxidase-labeled cells were seen although axodendritic contacts with horseradish peroxidase-labeled cells were predominant. Occasionally, leucine-enkephalin-like immunoreactive fibers with synapses on horseradish peroxidase-labeled neurons formed axoaxonic contacts with other leucine-enkephalin-like axonal terminals. Thus, substance P-, leucine-enkephalin- and serotonin-like fibers clearly regulate the function of cremaster motoneurons monosynaptically. The varied synaptic contacts of these fibers according to the neuroactive substances involved suggest different actions of these substances on the cremaster motoneurons.

Animals↗
PubMed1989

Distribution of the omega-conotoxin receptor in rat brain. An autoradiographic mapping.

The distribution of [125I]omega-conotoxin GVIA binding sites, the putative voltage-sensitive calcium channels, was studied by an autoradiographic method in the rat brain. The toxin binding sites were distributed throughout the brain in a highly heterogeneous manner. The highest density of the binding sites was observed in the cerebral cortex, hippocampus, amygdaloid complex, substantia nigra, caudate putamen, superior colliculus, nucleus of the solitary tract, and the dorsal horn of the cervical spine. The glomerular layer of the olfactory bulb, molecular layer of the cerebellar cortex, and posterior lobe of the hypophysis showed intermediate density but the density was higher than in the surrounding areas. The globus pallidus, thalamic areas, inferior olive, and pontine nuclei showed low density, while no binding sites were observed in the white matter tract regions such as the internal and external capsule, corpus callosum, fimbria of the hippocampus, fornix, stria medullaris of the thalamus, and fasciculus retroflexus. This distribution of omega-conotoxin binding sites indicates that the toxin binding sites are localized in those areas of the brain enriched in synaptic connections. This distribution pattern resembles that reported for voltage-sensitive sodium channels but it differs from that of the binding sites of dihydropyridines and verapamil. These results suggest that omega-conotoxin recognizes different molecules from organic calcium channel antagonist binding sites and that omega-conotoxin-sensitive voltage-sensitive calcium channels are concentrated in the synaptic zones and play a key role in the excitation-secretion coupling of neurotransmitters.

Animals↗
PubMed1989

Anatomical distribution of somatostatin immunoreactivity in the infant brainstem.

The distribution of somatostatin-immunoreactive structures in the infant brainstem was investigated using the peroxidase-antiperoxidase technique. A wide distribution of somatostatin-immunoreactive cell bodies and fibers was observed throughout the brainstem. Numerous somatostatin-immunoreactive cell bodies and fibers were present in several areas of the brainstem including the substantia grisea centralis and the reticular formation. Some immunoreactive cell bodies were seen in cranial nerve nuclei such as the nucleus praepositus, the nucleus nervi hypoglossi and the vestibular nuclei. Immunoreactive fibers were seen in the nucleus cuneatus, the locus coeruleus, the nucleus tractus solitarius, the nucleus ambiguus, the nucleus tractus spinalis nervi trigemini and the dorsal horn of the spinal cord. These data were in agreement with previous works on the human adult. However, a high density of somatostatin-immunoreactive cell bodies and fibers in the interpeduncular nucleus and in the nucleus centralis superior, and a dense network of somatostatin-immunoreactive fibers in the dorsal part of the nucleus inferior olivarius, were also observed. The role of somatostatin in some brainstem nuclei and its probable implication in some specific neuropathological diseases of the infant brainstem is discussed.

Brain Stem↗
PubMed1989

Interaural cross-correlation coefficients in stereo-reproduced sound fields.

Interaural cross-correlation coefficients (ICCCs) were measured in stereo-reproduced fields where a KEMAR (Knowles electric manikin for acoustic research) was located. These ICCCs were then compared with those in an ideal, diffuse sound field. The ICCCs in a reverberant field are not reproduced accurately using a conventional two-channel stereo-reproduction technique. In four-channel stereo reproduction, however, the ICCCs can, for the most part, be reproduced accurately as in an ideal, diffuse sound field. Some experimental results are also shown for binaural discrimination of the ICCCs.

Acoustics↗