Somatostatin cell

The oxyntic gland is the secretory unit of the gastric mucosa. The acid-secreting parietal cells are located in the wall of its midsection. In addition to parietal cells, these glands consist of mucous-secreting superficial and neck cells, pepsinogen-secreting chief cells, endocrine, and somatostatin cells [1]. 

Augood SJ, McGowan EM, Emson PC (1994) Expression of A-methyl-D-aspartate receptor subunit NRl messenger RNA by identified striatal somatostatin cells. Neuroscience 59 7-12. 

The pancreas is a large organ containing exocrine and endocrine tissue. The islets of Langerhans make up the endocrine part and contain cells that produce insulin, glucagon and somatostatin. Cells that produce glucagon (a-cells) and somatostatin (D-cells) are found peripherally in the islets while the predominant insulin producing cells (f)-cells) are found in the centre. 

Larsson H, Golterman N, De Magistris L, et al. Somatostatin cell processes as pathways for paracrine secretion. Science 1979 205 1393. Lewin MJM. The somatostatin receptor in the Gl tract. Ann Rev Physiol 1992 54 455. 

The hormone pancreatic polypeptide (PP) is a 36 amino acid peptide, which is closely related to neuropeptide Y and peptide YY PP is mainly found in pancreatic cells distinct from those storing insulin, glucagon or somatostatin. It acts on receptors that belong to the family of neuropeptide Y receptors, particularly on the Y4 subtype. 

Somatostatin is a regulatory cyclic peptide, which has originally been described as a hypothalamic growth hormone release-inhibiting factor. It is produced throughout the central nervous system (CNS) as well as in secretoty cells of the periphery and mediates its regulatory functions on cellular processes such as neurotransmission, smooth muscle contraction, secretion and cell proliferation via a family of seven transmembrane domain G-protein-coupled receptors termed sstx 5. 

High amounts of somatostatin are found in the CNS, the peripheral nervous system, the gut and the endocrine pancreas whereas the kidneys, adrenals, thyroid, submandibular glands, prostate and placenta produce rather low amounts. In particular, the hypothalamus, all limbic structures, the deeper layers of the cerebral cortex, the striatum, the periaqueductal central grey and all levels of the major sensoty pathway are brain areas that are especially rich in somatostatin. Eighty percent of the somatostatin immunoreactivity in the hypothalamus is found in cells of the anterior periventricular nucleus (Fig. 1, [1]). The gut 5 cells of the mucosa and neurons, which are intrinsic to the submucous and... 

Somatostatin acts on various organs, tissues and cells as neurotransmitter, paracrine/autocrine and endocrine regulator on cell secretion, smooth muscle contractility, nutrient absorption, cell growth and neurotransmission [1]. Some of its mainly inhibitory effects are listed in Table 1. Somatostatin mediates its function via a family of heptahelical G-protein-coupled receptors termed... 

The diverse effects of somatostatin, such as inhibition of cell proliferation and hormone release, led to the suggestion that it could be used for the treatment of various diseases. However, its short plasma half-life (less than 3 min) and its relative low receptor subtype... 

Sun L., Fuselier J.A., Murphy W.A., Coy D.H. Antisense peptide nucleic acids conjugated to somatostatin analogs and targeted at the n-myc oncogene display enhanced cytotoxity to human neuroblastoma 1M.R.32 cells expressing somatostatin receptors. Peptides 2002 23 1557-1565. 

The synthesis and characterization of a somatostatin receptor-specific peptide H2N-(DPhe)-cyclo[Cys-Phe-(D-Trp)-Lys-Thr-Cys]-Thr-OH, labeled with an indo-dicarbo- and an indotricarbocyanine dye at the V-terminal amino group were described in [34], The ability of these fluorescent contrast agents to target the somatostatin receptor was demonstrated by flow cytometry in vitro, wherein the indotricarbocyanine conjugate led to elevated cell-associated fluorescence on somatostatin receptor-expressing tumor cells. The intracellular localization was visualized using NIR fluorescence microscopy. 

The desensitization of the fi receptor was heterologous. In oocytes cotransfected with ft and serotonin receptors, chronic morphine treatment abolished morphine and serotonin potentiation of the K+ current [63]. Similarly, in AtT-20 cells transfected with the cloned fi receptor, chronic DAMGO treatment abolished the ability of opiates and somatostatin, acting via endogenous somatostatin receptors in these cells, to stimulate K+ conductance [65]. 

When the gastritis induced by H. pylori is confined to the antrum, the increase of gastrin and the reduction of somatostatin released by the G and D cells in the antrum, respectively, will increase the drive for acid secretion from the preserved oxyntic mucosa [45]. This increased... 

Stress-related immune dysregulation also involves the synthesis of hormones including ACTH, growth hormone, and prolactin.14-17 Interestingly, it has also been demonstrated that various aspects of the immune response, for example., proliferation of B- and T-cells, cytokine production, antibody production, chemotaxis of monocytes and neutrophils, and natural killer (NK) cell cytotoxicity, can be affected by glucocorticoids (including cortisol) as well as peptides such as ACTH, CRH, endorphins, substance P, and somatostatin.1218... 

Patel, R. C Kumar, U Lamb, D. C., et al. (2002) Ligand binding to somatostatin receptors induces receptors-specific oligomer formation in live cells. Proc. Natl. Acad. Sci. USA 99, 3294-3299. 

The sensory neuropeptides, SP, calcitonin-gene-related peptide (CGRP) and somatostatin (SOM) rapidly release histamine from rat serosal mast cells by a non-cytotoxic mechanism [3, 62],... 

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