Search results for "chromogranin"
showing 7 items of 37 documents
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 …
Cytoskeleton mediates negative inotropism and lusitropism of chromogranin A-derived peptides (human vasostatin1-78 and rat CgA(1-64)) in the rat heart
2010
Cytoskeleton scaffold in cardiac myocytes provides structural support and compartmentalization of intracellular components. It is implicated in cardiac pathologies including hypertrophy and failure, playing a key role in the determinism of contractile and diastolic dysfunctions. Chromogranin A (CgA) and its derived peptides have revealed themselves as novel cardiovascular modulators. In humans, normal CgA levels considerably increase in several pathologies, including heart failure. Recent data have shown on the unstimulated rat heart that human recombinant Vasostatin-1 (hrVS-1) and rat chromogranin A 1-64 (rCgA(1-64)) induce negative inotropic and lusitropic effects counteracting the beta-a…
Catestatin-like immunoreactivity in the rat eye
2014
The aim of the study was to investigate the presence and distribution of the chromogranin A-derived peptide catestatin in the rat eye and trigeminal ganglion by immunofluorescence using an antibody which recognizes not only free catestatin but also larger fragments containing the sequence of catestatin. Western blots were performed in an attempt to characterize the immunoreactivities detected by the catestatin antiserum. Sparse immunoreactive nerve fibers were visualized in the corneal stroma, in the chamber angle, in the sphincter muscle but also in association with the dilator muscle, in the stroma of the ciliary body and processes, but dense in the irideal stroma, around blood vessels at…