Search results for "chromogranin A"
showing 10 items of 32 documents
Distribution and coexistence of chromogranin A-, serotonin-and pancreastatin-like immunoreactivity in endocrine-like cells of the human anal canal
1992
The comparative distribution and coexistence of chromogranin A (CGA)-, serotonin (5-hydroxytryptamine; 5-HT)- and pancreastatin (PST)-like immunoreactivity in endocrine-like cells of the human anal canal was investigated by light-microscopic immunocytochemistry. The largest population of colorectal endocrine-like cells consisted of CGA-immunoreactive (ir) cells, followed by the 5-HT-ir and PST-ir cell population. In the anal transitional zone (ATZ), CGA- and 5-HT-immunoreactivity was equally distributed; ir-PST was confined to a smaller endocrine-like cell population. In the squamous zone and the perianal skin, Merkel cells in the basal layer of the epidermis and hair follicles exhibited ir…
Inhibitory influence of chromogranin A N-terminal fragment (vasostatin-1) on the spontaneous contractions of rat proximal colon
2005
Very little is known about the role played by CGA and its fragments in the gastrointestinal physiology. We have studied the role of CGA N-terminal fragments in the regulation of intestinal smooth muscle contractility by measuring the influence of recombinant CGA 1-78 (VS-1) and synthetic CGA 7-57 peptides on the spontaneous mechanical activity of rat proximal colon in vitro. The mechanical activity was recorded as changes in the intraluminal pressure. VS-1 (0.1-30 nM) and CGA 7-57 (10-300 nM) produced concentration-dependent inhibitory effects, characterized by a progressive decrease in the mean amplitude of circular muscle spontaneous contractions, without affecting the resting tone. The r…
Immunohistochemical localization of the pro-peptide processing enzymes PC1/PC3 and PC2 in the human anal canal.
1997
Abstract HORsch, D., R. Day, N. G. Seidah, E. Weihe and M. K.-H. SchAFer. Immunohistochemical localization of the pro-peptide processing enzymes PC1/PC3 and PC2 in the human anal canal. Peptides 18(5) 755–760, 1997.—The distribution of prohormone/pro-peptide convertases PC1/PC3 and PC2 was investigated in the human anal canal by immunohistochemistry. Both prohormone convertases exhibited region-specific distribution patterns and were observed in neural and neuroendocrine cells and in nonneuroendocrine cellular elements. PC1/PC3 immunoreactivity was present in enteric neurons, subsets of nerve fibers, and neuroendocrine cells, and also in epithelial cells like intestinal stem cells, and a su…
Electron microscopic immunogold cytochemistry reveals chromogranin A confined to secretory granules of porcine Merkel cells
1990
By ultrastructural immunohistochemistry using the immunogold technique, immunoreactive (ir) Chromogranin A (CGA) was found to be confined to the secretory vesicles of porcine Merkel cells. CGA was present predominantly in the periphery of the electron-dense core and on the clear halo. These findings indicate that CGA is a regular constituent of Merkel cell secretory granules but probably not exclusively responsible for their electron opacity.
Chromogranin A in the Mammalian Merkel Cell: Cellular and Subcellular Distribution
1989
Chromogranin-A (CGA), which accounts for more than half the soluble matrix protein in secretory granules of various neuroendocrine cells, has a wide spectrum of potential biological roles and is considered an important marker of the diffuse neuroendocrine system (DNES). Light and electron microscopic immunohistochemistry of mammalian skin revealed that Merkel cells are exclusively CGA-immunoreactive (ir) and that the immunoreaction is localized in the secretory granules. This finding supports the classification of the Merkel cell as a member of the DNES. The CGA immunoreactivity was restricted to Merkel cells of pigs and humans. In human embryonic skin, CGA was expressed in Merkel cells as …
Chapter 20 Multiple messenger candidates and marker substances in the mammalian Merkel cell – axon complex: a light and electron microscopic immunohi…
1988
Publisher Summary This chapter discusses multiple messenger candidates and marker substances in the mammalian merkel cell—axon complex. According to the APUD theory, cells of the diffuse neuroendocrine system (DNES) are essentially characterized by containing amines, peptides and marker substances like neuronspecific enolase (NSE) and chromogranin A (CGA). By the comparison of the histotopography of immunostained peptides, CGA and neuroendocrine markers, there was an expectation to find out the most appropriate immunohistochemical marker of the Merkel cell and to get further insight into the complex chemo-anatomy and possible functional spectrum of the Merkel cell -axon complex at various d…
New biological aspects of Chromogranin A-derived peptides: Focus on vasostatins
2007
Chromogranin A (CgA), one component of the granin family, represents the major soluble protein co-stored and co-released with catecholamines, within chromaffin cells secretory granules. It is considered a diagnostic and prognostic marker of several diseases, including a variety of tumours and cardiac heart failure. It also represents a precursor of biologically active fragments, generated after proteolytic cleavage at the level of the multiple pairs of dibasic sites which enrich its sequence. CgA, and its derived fragments show an old evolutionary history being ubiquitously present throughout the animal word, from mammals to invertebrates. Their biological functions include control of hormo…
Human recombinant vasostatin-1 may interfere with cell-extracellular matrix interactions
2006
Vasostatin-1 (VS-1), the N-terminal fragment derived from the cleavage of chromogranin A (CgA), has been shown to exert several biological activities on several tissues and organs. Recently, it has been reported that human recombinant VS-1 (STA-CGA(1-78)) may alter myocardial contractility in eel, frog., and rat hearts. In this article we have explored if STA-CGA(1-78) can induce intracellular cascades interacting both with adhesion molecules and/or extracellular matrix (ECM), components, that is, involvement of the heat shock protein 90 (HSP90) and the endothelial NOS (eNOS), known to be implicated in signal transduction mechanisms affecting myocardial contractility. We used 3D cultured ad…
Relaxation induced by N-terminal fragments of chromogranin A in mouse gastric preparations.
2007
Abstract A definitive role for chromogranin A (CGA)-derived fragments in the control of the gastrointestinal smooth muscle contractility has not been yet established. The purpose of the present study was to evaluate, in vitro , the effects of the recombinant vasostatin 1–78 (VS-1), CGA 7–57 and CGA 47–66 on the mouse gastric mechanical activity, recording the changes of intraluminal pressure. VS-1, CGA 7–57 and CGA 47–66 produced concentration-dependent relaxations. Mouse anti-vasostatin-1 monoclonal antibody 5A8, recognising the region 53–57, abolished the relaxation induced by VS-1, indicating the specificity of the effect. The relaxation was significantly reduced by tetrodotoxin (TTX), b…
Neuroendocrine tumor of the common bile duct: case report
2017
Neuroendocrine tumors (NET) are a very heterogeneous group of neoplasms; in recent years we have seen an increase in their incidence (3.65 /100.000/year). They can be associated with hereditary endocrine syndromes (MEN, Von Hippel Lindau); they can occur at any age and the incidence is slightly higher in men than women. The aetiology of the neuroendocrine tumors is unclear; in most cases, inflammation of the bile ducts may be the underlying cause and for this reason, the initial patient's evaluation should be focused on the different aspects concerning the oncological one and the possible sequelae of the biliary obstructions that can evolve in biliary sepsis. All neuroendocrine tumors have …