ISSN:1059-910X    

DOI:10.1002/jemt.1070290202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe distribution of neurons that are capable of synthesizing nitric oxide (NO) has been demonstrated in the porcine large intestine by means of NO synthase (NOS) immunocytochemistry and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry. An overall colocalization of NOS immunoreactivity and NADPHd staining was observed. Nitrergic neurons were abundant in the myenteric and outer submucous plexus of the caecum, colon, and rectum. Only a few nitrergic perikarya were seen in the inner submucous plexus of the colon and caecum, whereas a substantially larger number was observed in the rectum. Nitrergic nerve fibers were present in the three ganglionic nerve plexuses. Contrary to the outer longitudinal muscle layer and the mucosal region, the circular muscle layer received a dense nitrergic innervation. The nitrergic nerve cells were variable in size and shape, and several displayed vasoactive intestinal polypeptide (VIP) immunoreactivity (IR). Retrograde tracing studies revealed the existence of nitrergic neurons that project to the caudal (inferior) mesenteric ganglion. They were observed in the myenteric and outer submucous plexus of the transverse and descending colon and the rectum. These observations strongly suggest that several subpopulations of NO‐synthesizing neurons, namely, motor neurons and interneurons, should be distinguished in the porcine large intestine, thereby emphasizing the importance of NO as a biologically active mediator. © 1994 Wiley‐Liss,

ISSN:1059-910X    

DOI:10.1002/jemt.1070290203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe respiratory tract of urodeles harbours an intramural nerve network comprising an innervated system of neuroepithelial endocrine (NEE) cells. However, striking differences have been noted between phylogenetically closely related species. Zamboni‐ or formaldehyde‐fixed whole‐mount preparations and sections of the saclike lungs of a Japanese salamander,Cynops pyrrhogaster, have been investigated for the immunocytochemical detection of nitric oxide synthase (NOS), serotonin (5‐HT), VIP, somatostatin, calcitonin, and bombesin; for the enzyme‐cytochemical demonstration of NADPH diaphorase (NADPHd); and for formaldehyde‐induced fluorescence. In addition, the ultrastructural morphology has been examined by using glutaraldehyde/osmium tetroxide fixed lung tissues. Ovoid 5‐HT‐immunoreactive (IR) NEE cells occur singly or grouped in the ciliomucous epithelium of the trachea and lungs ofCynops, and a few somatostatin‐, calcitonin‐, and bombesin‐like IR NEE cells are also observed. These cells exhibit a characteristic neuroendocrine morphology as seen with the electron microscope. In addition, large numbers of 5‐HT‐IR interstitial cells, with round to oval cell bodies and two or three long, slender, sometimes branching processes, are located preferentially along large blood vessels in the connective tissue capsule of the lung and trachea. Immunoelectronmicroscopy shows that 5‐HT is localized over large dense granules in the cell bodies and processes of these interstitial cells. NOS‐like immunoreactivity occurs in a nerve plexus composed of thick nerve bundles and nerve cells, and in a fine varicose nerve network that originates at least partly from intrapulmonary NOS‐containing nerve cells. VIP‐like immunoreactivity appears to be colocalized with NOS in the latter network. All NOS‐positive nerve fibres in the lungs ofCynops pyrrhogasterandAmbystoma mexicanumstain for NADPHd. It is concluded that the pulmonary NEE cells observed inCynops pyrrhogasterare similar to those described in other vertebrate species and that the 5‐HT‐IR interstitial cells resemble mast cells. In addition, nitric oxide is likely to be a bioactive substance involved in nonadrenergic, noncholinergic inhibitory neurotransmission in the pulmonary nervous system of urodeles, where it may be coloc

ISSN:1059-910X    

DOI:10.1002/jemt.1070290204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe morphology and function of the carotid sinus and carotid body have been extensively studied, but our knowledge of their transmitter(s) is still incomplete. Nitric oxide (NO) recently has been identified as a novel messenger molecule in a number of neuronal and non‐neuronal tissues. Nitric oxide synthase (NOS) has been demonstrated in many neurons of the autonomic nervous system. The present study examines the distribution of NOS in the carotid sinus and body. The carotid sinus and body of newborn guinea pigs were removed for histochemical examination of NOS using the NADPH‐diaphorase method. In the carotid body, many nerve fibers enveloping the glomus cells were positive for NOS. In addition, some glomus cells were positive for NOS. In the carotid sinus, NADPH‐d positive fibers were distributed unevenly in the adventitia and media. These results indicate the possibility that nitric oxide plays a role in both arterial chemoreception and baroreception. © 1994 Wiley‐L

ISSN:1059-910X    

DOI:10.1002/jemt.1070290205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractSuperior cervical ganglion neurons (SCGNs) were isolated from 7‐day‐old rat SCG and cultured in MEM containing horse serum, fetal calf serum, and nerve growth factor. In this culture condition, it is well known that the SCGNs form cholinergic synapse. In 3–4 weeks cultured neurons, immunofluorescent staining for synaptophysin, a small synaptic vesicle associated protein, showed the presence of synaptophysin as small dots on the surface of the soma. Postsynaptic potentials could be recorded in 50–80% of the neurons responding to evoked action potentials elicited in neighboring neurons. Because of its relatively large cell size and the short distance to the terminal, this synapse is a useful model for studying the mechanisms of acetylcholine (ACh) release by introducing substances such as antibodies or selective inhibitors into the presynaptic neuron by means of the whole‐cell clamp technique.In this model synapse we tested the possible role of myosin in ACh release. The distribution of myosin was studied by the immunofluorescent staining technique. Myosin was recognized by the anti‐myosin II IgG at the same synaptic terminals that showed the presence of synaptophysin with its antibody. The functional blockade of myosin by the antibody itself, and that of myosin light chain kinase (MLCK) by a pseudosubstrate inhibitor of MLCK, SM‐1, or by a selective inhibitor of MLCK, wortmannin, induced depression of synaptic transmission in a dose‐dependent manner. These indicate that phosphorylation of myosin by MLCK may be necessary for ACh release mechanisms. © 1994

ISSN:1059-910X    

DOI:10.1002/jemt.1070290206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractUsing acetylcholinesterase (AChE), nicotinamide adenine dinucleotide diaphorase (NADHd), and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) enzyme histochemical techniques, the ganglionated plexuses of the porcine enteric nervous system were investigated in small intestine whole‐mount preparations. Both AchE and NADHd techniques revealed a majority of the neurons in the ganglia of all three major plexuses. The AchE technique also demonstrated clearly the axodendritic networks of the plexus myentericus. Intraganglionic blank areas revealed the localization of negative cell groups. A very high correlation was found between the activity of both enzymes in one neuron, although this correlation was certainly not linear. Many neurons exhibited a stronger signal for one enzyme. A very small part of the positive nerve cells showed intense staining for both AchE and NADHd. The NADPHd technique demonstrated that the NADPHd‐positive neurons fill the negative intraganglionic spaces in the ganglia. Double staining with the two other enzymes showed virtually no colocalization of NADPHd with either NADHd or AchE in the porcine jejunal enteric ganglia. Little negative intraganglionic spaces were seldom found, leaving room for perhaps still more negative enteric neurons. Based upon these results we suggest that the enteric neurons of the porcine small intestine can be subdivided into AchE‐NADHd and NADPHd subpopulations. Since the latter colocalizes with the neuronal NO synthase enzyme, we further suggest a subdivision of the enteric nerve cells into AchE‐NADHd and NOS‐NADHd neurons. © 1994 Wiley

ISSN:1059-910X    

DOI:10.1002/jemt.1070290207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractChemosensitivity and plasticity of paraganglionic cells in the rat coeliac‐superior mesenteric complex (CSMC) were investigated at a basal state of normoxia (21% O2) and after long‐term moderate hypoxia (10% O2, 14 days). Chemical sympathectomy previous to hypoxia was performed to destroy principal ganglionic neurons and thus to allow measurement of the norepinephrine and dopamine content of paraganglionic cells.At the basal state, the CSMC contained dopaminergic (TH+/DBH−) and noradrenergic (TH+/DBH+) paraganglionic cells, the majority being of the noradrenergic type. After 14 days of hypoxia, this ratio was reversed and dopaminergic cells predominated, as indicated by a twofold increase of TH+cells and a twofold decrease of DBH+cells. Biochemically, hypoxia produced an increase in the content (1.6‐fold) and utilization (1.4‐fold) of dopamine as well as a smaller increase in the content of norepinephrine, with no change in its utilization rate. The dopaminergic activation induced by hypoxia persisted after sympathectomy with guanethidine.It is concluded that paraganglionic cells in the CSMC display a chemosensitive function. Furthermore, our findings indicate that paraganglionic cells are differentially affected by hypoxia, depending on their distribution and the nature of their neuromodulators. The alterations induced by hypoxia point out the phenotypic plasticity developed by paraganglionic cells in adaptation to hypoxia and further demonstrate the functional heterogeneity of this autonomic cell population in the rat CSMC. © 1994 Wiley

ISSN:1059-910X    

DOI:10.1002/jemt.1070290208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe neuropeptides galanin (GAL) and vasoactive intestinal polypeptide (VIP) are upregulated in spinal and vagal sensory as well as in cranial motor neurons after axonal transection. In this study an increase of both peptides is demonstrated in axotomized principal ganglionic neurons (PGN) of the rat sympathetic superior cervical ganglion by use of double‐labeling immunofluorescence. Compared to control ganglia that do not contain more than 1% GAL‐ or VIP‐positive cells, about 26% of all PGN exhibit GAL immunoreactivity by day 1 after transection of the major postganglionic branches. The proportion of immunoreactive neurons reaches its maximum after 30 days (40%) and decreases to about 27% within the second month after axotomy. The percentage of VIP‐positive neurons is much lower than for GAL: 2% of the PGN exhibit VIP immunoreactivity at day 1 and about 7% are observed 30 and 60 days after axotomy. In order to further characterize newly GAL‐ and VIP‐positive PGN, their cell diameters were determined 12 days after axotomy. Compared to the mean overall neuron diameter of 24.8 μm, GAL‐immunoreactive neurons are predominantly of small and intermediate size (22.2 μm), whereas VIP occurs mainly in larger neurons (26.1 μm). Besides cell bodies, many intraganglionic nerve fibers stain positive for GAL or VIP, particularly at day 6. Most likely, these fibers represent axons, as indicated by the absence of MAP2, a cytoskeletal protein found in neuronal somata and dendrites. They establish direct membrane contacts with postganglionic perikarya, as revealed by pre‐embedding immuno‐electron microscopy. Some cell bodies and fibers contain both peptides. Colocalization of GAL or VIP with tyrosine hydroxylase (TH), the rate‐limiting enzyme of catecholamine synthesis, reveals a reduced immunoreactivity for TH in intensely GAL‐ or VIP‐positive cells, and vice versa at day 6. However, no difference in staining intensity for VIP or GAL, and TH, is observed after 30 and 60 days. Possible implications of GAL and VIP for peripheral nerve regeneration and their regulation by target‐derived factors are discu

ISSN:1059-910X    

DOI:10.1002/jemt.1070290209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractUsing the indirect immunofluorescence method, the distribution of galanin (GAL)‐ and galanin message‐associated peptide (GMAP)‐like immunoreactivities (LI) were studied in sympathetic ganglia and the adrenal gland of the guinea pig. A rather dense network of GAL‐immunoreactive nerve fibers was found in the inferior mesenteric ganglion (IMG) and in the superior mesenteric pole of the celiac‐superior mesenteric ganglion complex (C‐SMG). The celiac pole of the C‐SMG, the stellate ganglion, and the superior cervical ganglion contained fewer, mostly scattered fibers. SIF‐cells in prevertebral and paravertebral ganglia contained GAL‐LI, as did the adrenal medullary cells. The GAL fibers in the IMG surrounded mainly principal ganglion cells containing somatostatin‐immunoreactivity (SOM‐IR), whereas fewer fibers were seen around neuropeptide Y (NPY) cells and cells in which SOM and NPY coexisted. Application of colchicine or vinblastine onto the IMG did not result in the appearance of GAL‐IR in the principal ganglion cells. In denervation experiments it was revealed that most of the GAL fibers reach the IMG via the lumbar splanchnic nerves.GAL‐IR appears to be colocalized with substance P (SP) in fibers of the IMG, indicating an origin of the GAL‐containing fibers in dorsal root ganglia (DRG). This conclusion was supported by the finding in lumbar DRGs of GAL‐positive cell bodies that contained SP. The role of GAL in prevertebral ganglia is unclear. It may be suggested that GAL modulates the slow, long‐lasting membrane depolarization of the principal ganglion cells caused by SP in the primary afferents related to the IMG. GMAP‐LI was detected in SIF cells and adrenal medullary cells in which GMAP‐LI parallels the immunoreactivity of GAL. GMAP‐LI was not observed in neuronal cell bodies or nerve fibers o

ISSN:1059-910X    

DOI:10.1002/jemt.1070290210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractDouble‐labelling immunofluorescence was applied on single sections of the rat superior cervical ganglion to evaluate neurochemistry and connectivity of intraganglionic SIF cells. The synaptic vesicle membrane protein synaptophysin and secretoneurin, a newly discovered neuropeptide derived from secretogranin II, proved reliable molecular markers of this cell type, whereas serotonin and tyrosine hydroxylase immunoreactivities were observed in slightly incongruent SIF cell subpopulations. Immunolabelling for vasoactive intestinal polypeptide and neuropeptide Y occurred in few SIF cells. None of the above immunoreactivities were visibly altered by preganglionic or postganglionic denervation, while some SIF cells were immunolabelled for galanin or for the neuronal microtubule‐associated protein MAP2 after postganglionic denervation. SIF cells were nonreactive for the pan‐neuronal marker protein gene product (PGP) 9.5 or neurofilament 160 kD. Intense staining of NADPH‐diaphorase in some SIF cells, suggesting catalytic activity of nitric oxide synthase, could not be substantiated by immunoreactivity for this enzyme. SIF cells were approached by nonidentical fiber populations immunoreactive for PGP 9.5, neurofilament, or neuropeptide Y, whereas immunoreactivities for galanin and vasoactive intestinal polypeptide were colocalized in fiber meshes around SIF cells. The findings indicate (1) neurochemical SIF cell heterogeneity, (2) SIF cell plasticity in response to ganglionic perturbation, and (3) a differentiated innervation of SIF cells in the rat superior cervical ganglion. © 1994 Wiley

ISSN:1059-910X    

DOI:10.1002/jemt.1070290211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY