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W Stach

Publications and source records attributed to W Stach.

At least 37 records · Page 2Linked to original sources
PubMed1986

Do B cells and peri-insular acinar cells of canine pancreas have nerves in common?

Synapses providing simultaneous contact with insulin-producing B cells and acinar cells have been found at the margins of islets of Langerhans in the dog. Blood vessels have also been observed in the vicinity of such synapses. The frequently described correlation between insulin and protein secretion might be a result of the simultaneous influence of these nerve endings on both enzyme- and hormone-producing cells.

Animals↗
PubMed1986

Innervation of the canine pancreas after vagotomy.

This contribution deals with the ultrastructure of the pancreatic nervous system of the dog 14 days and 5 months after bilateral truncal vagotomy. No major ultramorphological changes in the axons or their organelles (vesicles, mitochondria, microtubuli) were observed, and there appeared to be no reduction in the numbers of sympathic and cholinergic axis cylinders (material fixed in glutaraldehyde and potassium permanganate) or neurocellular contacts.

Animals↗
PubMed1986

Three-dimensional organization and topographical features of the myenteric plexus (Auerbach) in the porcine small intestine: scanning electron microscopy after enzymatic digestion and HCl-hydrolysis.

The present scanning electron microscopical (SEM) study was initiated to visualize the surface topography of Auerbach's plexus in the ileum of the pig. After enzymatic digestion of the connective-tissue components of the tunica muscularis and the tunica serosa followed by glutaraldehyde fixation, HCl-hydrolysis and stripping off either the longitudinal or circular smooth muscle layer, the three-dimensional architecture and topographical features of the myenteric plexus can clearly be observed. In this way, ganglia, primary, secondary and tertiary strands, and single nerve fibres can be demonstrated. Individual nerve cells, which are incompletely covered by glial cells and by remnants of the basal lamina, can be recognized in the centre and periphery of the ganglia and adjacent to primary and secondary nerve strands.

Animals↗
PubMed1986

Are the islets of Langerhans neuro-paraneuronal control centers of the exocrine pancreas?

The authors investigate whether the islets of Langerhans can actually be regarded as "neuro-paraneuronal control centers of the exocrine pancreas" as was first suggested by Fujita and Kobayashi (1979). The question is discussed on the basis of the authors' electron microscopic findings regarding pancreatic innervation before and after truncular vagotomy. The results do not seem to support the above hypothesis which advocates that the intrainsular axons are principally engaged in the release of their transmitters into the capillaries in order to regulate, via the insuloacinar portal vessels, the exocrine function of the pancreas. On the contrary, the present data draw attention to the unambiguous assignation of intrainsular axons to endocrine cells, a point of question in line with several findings published in the literature including papers by the first supporters of this hypothesis. No change was observed in the innervation pattern of the effector cells after vagotomy.

Animals↗
PubMed1986

[Electron microscopy and ultrahistochemical studies on the innervation of the vagotomized dog pancreas].

The ultrastructural features of axon profiles and synapses within islets of Langerhans and pancreas have been examined after a bilateral truncular vagotomy (1, 2 and 20 weeks). The results are as follows: The cholinergic and noradrenergic axons were not reduced according to controls. The integrity of neuro-cellular synapses was unchanged in the pancreas and islets of Langerhans. Intrinsic axon profiles formed synapses with A- and B-cells and acinous cells 2 or 20 weeks after vagotomy. It is concluded that the innervation of the endocrine and exocrine pancreas cells remains unchanged after extrinsic denervation (vagotomy).

Adrenergic Fibers↗
PubMed1986

[Bisynaptic connection in an insulin-producing B-cell].

The islets of Langerhans of the dog are an example of a close combination of endocrine and nerve tissue. Our figure shows the innervation of a insulin producing B cell by a cholinergic and a peptidergic axon simultaneously.

Animals↗
PubMed1985

A simultaneous demonstration of particular enteric neuronal cell types with the NADH:nitro BT-dehydrogenase reaction and of nerve fibres containing enkephalin-like immunoreactivity in the myenteric plexus of the porcine small intestine.

The myenteric plexus of the porcine small intestine is studied using a combined method for the simultaneous visualization of enteric intramural neuronal cell bodies and peptidergic nerve fibers. As earlier reported, the histochemical method for demonstration of the NADH-dependent dehydrogenase reaction allows the identification of the three neuron types of Dogiel but, in addition, the afore mentioned staining method creates fair conditions in the tissue for the subsequent indirect immunocytochemical visualization of neuropeptides, as demonstrated in this work by means of the indirect immunofluorescence method for enkephalin-like immunoreactivity. Intense fluorescent varicosities of enkephalin-like nerve fibres were found to ramify around dark-blue stained ganglionic cells of type I, type II and type III in a manner suggestive of innervation.

Animals↗
PubMed1985

NADH-dehydrogenase reaction in combination with immunoperoxidase (PAP) staining for light microscopic observation on the interneuronal relations of the enteric nervous system of the pig.

A novel procedure for a simultaneous demonstration of particular enteric nerve cell types and peptidergic nerve fibres has been developed by combining the histochemical reaction for NADH-dependent dehydrogenase and the unlabelled antibody peroxidase-antiperoxidase (PAP) method described by Sternberger. Whole-mount spreads were successively incubated in a NADH: nitroblue tetrazolium solution, fixed with a picric acid/formaldehyde mixture, dehydrated, cleared and rehydrated before processing for immunocytochemical localization of the neuropeptide by the PAP method. The nerve cells appear heavily stained by deposits of dark blue formazan, whereas the peptide-containing nerves appear bright brown. In the myenteric and submucous plexuses of the porcine small intestine the devised method allows an appropriate identification of Dogiel's type I, type II and type III neurons surrounded by varicose enkephalin-like immunoreactive fibre baskets with button-like twigs to the very surface of the ganglionic cells, suggestive of synaptic connections.

Animals↗
PubMed1985

[Cephalic insulin secretion--neuromorphologic findings].

The paper presented deals with the electron microscopy bases of experimental results, which show a cephalic insulin secretion. The B cell-producing insulin--is a highly innervated endocrine cell. Several nerve endings often form synaptic connexions at a single B cell. The synaptic clefts are usually 20-25 nm. The nerve endings cause an evident impression of the cell membrane. The narrow neuro-cellular connexions form a structural bases of the cephalic insulin response. The interruption of this reflex loop caused by vagotomy eliminates cephalic mechanism. However, the innervation of the islets (electron microscopic examination) remains unaffected. Therefore the intramural nervous mechanism seems to be not excluded by vagotomy.

Animals↗
PubMed1984

Fluorescence microscopic study of the architecture and structure of an adrenergic network in the plexus myentericus (Auerbach), plexus submucosus externus (Schabadasch) and plexus submucosus internus (Meissner) of the porcine small intestine.

The distribution of adrenergic fibres in the ganglionated plexuses of the porcine small intestine has been made on air-dried stretch preparations using the glyoxylic acid fluorescence method. Adrenergic fluorescent fibres occur in the ganglia and internodal strands of the three fundamental ganglionated plexuses: the myenteric plexus (Auerbach) and the two superimposed meshworks of the plexus submucosus , i.e. the plexus submucosus externus ( Schabadasch ) and the plexus submucosus internus (Meissner). The plexus Auerbach consists of densely glyoxylic acid induced fluorescent (GIF) elongated ganglia with in general a longitudinal axis running parallel to the circular muscle layer and large dense interconnecting fibre tracts with primary, secondary and tertiary subdivisions. In the ganglia, the fibres are varicose, forming large fluorescent 'baskets' which might be related to the occurrence of well defined enteric neurones. The plexus Schabadasch can be distinguished from the plexus Meissner by its size, strongly fluorescent ganglia and broad densely fluorescent internodal strands. The pattern of fluorescing ring-like formations at the margin and out of the nodes, clearly present in the Auerbach and Schabadasch plexuses, completely lack in the plexus Meissner, the latter being narrow-meshed with smaller fluorescent 'baskets', indicating that the corresponding neurones are smaller in size. In the ganglionic nodes of all three plexuses the axons display comparatively more varicosities than in the fibre tracts. Each of the three main ganglionated enteric plexuses are quite different with regard to the pattern of the adrenergic network both in the ganglia and in the strands.

Animals↗
PubMed1983

External adrenergic innervation of the three neuron types of Dogiel in the plexus myentericus and the plexus submucosus externus of the porcine small intestine.

For the simultaneous demonstration of intramural enteric ganglion cells and the adrenergic nerve fibres in the porcine small intestine a combined histochemical method was developed using a hypertonic solution, the main chemicals of which were glyoxylic acid, Nitro-BT and NADH. By means of the enzymatic histochemical method reaction for the NADH-dependent dehydrogenase activity with Nitro-BT as an electron acceptor, the identification of the three neuron types of Dogiel (i.e. type I, type II, type III) was for the first time realized in relation with the glyoxylic acid induced fluorescence (GIF) of the plexus myentericus (Auerbach) and the plexus submucosus externus (Schabadasch). Besides the close topographic relationship between the adrenergic varicose axons on the one hand and the perikarya and dendrites of the multidendritic uniaxonal type I cells characterized by radially oriented short and lamellar dendrites and the multidendritic uniaxonal type III cells, characterized by radially oriented long and tapering dendrites on the other hand, it is striking that for the adendritic multiaxonal type II cells the fluorescent varicose fibres adhere closer to the cell bodies and their processes. In principle, the relation between adrenergic varicose axons and neuron types is identical in plexus myentericus (Auerbach) and plexus submucosus externus (Schabadasch), yet with the exception that in the latter no type I neurons are observed.

Adrenergic Fibers↗
PubMed1982

[Innervation of islands of Langerhans. Light and electron microscopic studies of the pancreas in laboratory animals].

A-, B- and D cells of the pancreas were found to be innervated. Moreover, at one and the same insular cell numerous and extended synapses are formed with very small synaptic clefts (less than 20 nm). It is ultrahistochemically detectable that A- and B cells are likewise sympathetically (adrenergically) innervated. Including specific data from the literature, the insular cell apparatus must be regarded as a organ which is highly controlled by the nervous system.

Adrenergic Fibers↗
PubMed1982

[Neuronal organization of the myenteric plexus (Auerbach) in the swine small intestine. III. Type III neurons].

Dogiel's type III-cells are a reality. According to our investigation they are characterized by the following mean features: 1. Type III-cells are radiate multidendritic (longdendritic, tapering) uniaxonal neurons. 2. Type III-neurons are frequent and represent a independent population of neurons. 3. Type III-cells are on principle concentrated in aggregates and are localized in the central and aboral parts of the ganglia. 4. The greater part of the neurits of type III-cells run aborally, i.e. there are typespecific descending routes within the plexus myentericus (Auerbach). 5. Type III-cells are preferred vascularized neurons.

Animals↗
PubMed1982

[Neuronal organization of the plexus myentericus (Auerbach) in the small intestine of the pig. IV. Type IV-Neurons].

In extension of Dogiel's neuron-typification there is demonstrated a 4th neuron-population (type IV-cells) of the nervous system of the intestinal wall. The elements of this population are mainly characterized as follows: 1. They are polar (up to radiate) multidendritic uniaxonal neurons with extremely marginal nuclei. 2. The type IV-neurons are organized in modified aggregates topographically related to the communicating branches between the plexus myentericus (Auerbach) and the plexus submucosus externus (Schabadasch). 3. The neurits of type IV-cells run through the communicating branches to the plexus Schabadasch, thus forming typespecific vertical routes within the nervous system of the intestinal wall. The morphological findings are discussed in relation to the most recent electrophysiological, immunohistochemical and autoradiographic results of other authors.

Animals↗
PubMed1981

[The neuronal organization of the plexus myentericus (Auerbach) in the small intestine of the pig. II. Typ II-neurone (author's transl)].

The population of type II-neurons in the Auerbach's plexus of the pig's small intestine consisting of bipolar, pseudo-unipolar, and multipolar elements could be characterized a.o. as follows: 1. The type II-cells are on principle concentrated in aggregates in the periphery and outside the ganglia. 2. The processes of type II-cells all leaving the ganglia or aggregates of origin, are of the same axonal structure. Considering further characteristics type II-cells are defined therefore as adendritic, multiaxonal neurons. 3. Contrary to the axons of the other multidendritic, uniaxonal types of neurons (type I, III, IV, V) those of type II-cells forming circular routes (besides the vertical ones) in the secondary branches of Auerbach's plexus can be followed up to the intramuscular plexus. That's why the type II-cells finally can be considered as adendritic, multiaxonal, and efferent neurons.

Animals↗
PubMed1980

[Neuronal organization of the myenteric plexus (Auerbach) in the small intestine of the pig. I. Type I neurons].

Examinations were done in silver impregnated strips of the small intestine of the pig. As a result of these findings we can state: 1. The real type I-neurons (according to Dogiel) are an integrated part (besides four other neuron-types) of the neuronal organization of the plexus myentericus (Auerbach). 2. There are uniaxonal multidendritic (short-dendritic) neurons, organized in aggregates as a rule. They are mainly found in the peripheric and oral parts of ganglia. The higher portion of neurits runs orally. These neurits form a type specific ascending tract. 3. The hitherto existing ideas on the neuronal organization of the intestinal nervous system are seriously doubted.

Animals↗