Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.7 (acetylcholinesterase)
 28,390 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Many questions concerning the morphology of the spleen have been cleared up in the last 20 years by the application of new methods of investigation, especially electron microscopy and enzyme histochemistry. With but a few exceptions, however, only the splenic parenchyma (the red and white pulp) were studied. Such special structures of the human spleen as nerves, lymphatic vessels and their supporting tissue, which may play an important role in the coordination and integration of the different functions of the white pulp (secondary lymphatic organ) and the red pulp (blood filter), were hardly ever studied with modern techniques. Investigating these structures light and electron microscopically and enzyme histochemically it was attempted to complete our present knowledge of the histology of the human spleen. In addition, by comparing the study of special altered spleens with experimental data it was attempted to clarify the importance of these structures for the physiology and pathology of the spleen. A total of 151 normal and pathologically altered spleens from the bioptic and autopsy material of the Pathological Institute of the University of Kiel were examined. In addition to conventional light microscopy the spleens were investigated enzyme histochemically and cytochemically, fluorescence microscopically and electron microscopically. The following enzyme reactions were done: Alkaline and acid phosphatase, alpha-naphthylacetate-esterase, naphthol-AS-acetate-esterase, 5'-nucleotidase, ATPase, and acetylcholinesterase. The various enzyme reactions were sometimes done in combination and reticulum and collagenous fibers were investigated by a subsequent staining of argyrophilic fibers. The fine localization of the 5'-nucleotidase activity was studied ultrahistochemically. Adrenergic nerve fibers were investigated fluorescence microscopically using the glyoxylic acid method.
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PMID:[Morphology and function of the human spleen. Enzyme histochemical and electron microscopy studies of the splenic lymphatic vessels, nerves and connective tissue structures]. 305 73

In the lymphatic vessels of man and most animals the nerve fibers are confined to the adventitia. However, immunohistochemical studies suggest that acetylcholinesterase-positive and monoamine-containing fibers reach as far as the endothelium in bovines. The aim of this study was to verify the presence of subendothelial nerve fibers by transmission electron microscopy (TEM) in bovine mesenteric lymphatics and to determine whether typical sensory neurotransmitters such as Substance P (SP) and calcitonin gene related peptide (CGRP) could be detected in these fibers. TEM revealed numerous unmyelinated nerve fibers in the subendothelial connective environment in close association with endothelial cells. Their axons were devoid of Schwann cell sheath on the endothelial side and contained small clear vesicles and large nerve fibers were demonstrated to be SP and CGRP-immunoreactive with mouse monoclonal antibodies against SP and rabbit polyclonal antibodies against CGRP. It is hypothesized that these fibers act as mechanoceptors capable of detecting intraluminal pressure and vessel wall tension variations and of locally releasing SP and CGRP. Since SP, potentiated by CGRP, is known to be a vasoconstrictor in lymphatics, we propose that the contraction of bovine mesenteric lymphatics may also be neurogenic.
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PMID:Subendothelial nerve fibers in bovine mesenteric lymphatics: an ultrastructural and immunohistochemical study. 752

A unique group of neurons in the submucous plexus of the gastrointestinal tract in guinea pigs was studied using (1) Nissl staining and an enzyme histochemical technique for acetylcholinesterase (AChE), (2) immunohistochemical methods for the localisation of neuron specific enolase (NSE) and neuropeptides, including vasoactive intestinal peptide (VIP), substance P (SP), somatostatin (SOM), calcitonin gene-related peptide (CGRP), leu-enkephalin (leu-ENK), neuropeptide (NPY) and cholecystokinin (CCK), (3) a fluorescence tracer technique involving the intraperitoneal (i.p.) injection of fluorogold, and (4) normal electron microscopy. The results showed that these neurons were distributed singly or in groups in the submucosa. They were closely adherent to the outer walls of lymphatic vessels, some appearing to protrude into the lumen. Ultrastructurally, only a thin layer of basal lamina and some collagen fibrils intervened between the endothelia of the lymphatic vessels and these neurons. Based on their synaptic contacts and the features of their content of synaptic vesicles, at least 4 types of axon terminal forming synaptic contacts with the 'lymphatic vessel-associated neurons' (LV-AN) were identified. The sources of origin of these terminals remains uncertain although it is speculated that they may be derived from vagal efferents or of intrinsic origin from the neighbouring neurons. All the LV-AN showed AChE and NSE positive reactions, but only a varying number were positive for VIP, SP, SOM, ENK, CGRP, CCK or NPY. The LV-AN were labelled with fluorogold injected i.p.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Studies of the lymphatic vessel-associated neurons in the intestine of the guinea pig. 755 16