Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Histologically normal liver biopsy specimens from patients with Hodgkin's lymphoma were investigated with three immunohistochemical methods for the occurrence of peptidergic nerve fibers and endocrine cells. Numerous immunoreactive nerve fibers were seen with antisera against peripheral nerves markers (neuron-specific enolase, neurofilament protein, and S-100). These nerve fibers were localized in the tunica media of branches of both the hepatic artery and portal vein, around the bile ducts, and in the connective tissue of the interlobular septa. In the liver, 10 types of peptidergic nerve fibers were detected: glucagon-, glucagon-like peptide- (GLP), somatostatin-, neuropeptide Y- (NPY), vasoactive intestinal polypeptide-, neurotensin-, gastrin/cholecystokinin C-terminus-, substance P-, serotonin-, and galanin-immunoreactive nerve fibers. GLP-, somatostatin-, NPY-, neurotensin-, substance P-, and galanin-immunoreactive nerve fibers were abundant; the other nerve fibers were scarce. The nerve fibers showed two distinct patterns of distribution: they occurred in the blood vessel wall and in connective tissue of the interlobular septum. Pancreatic polypeptide- and NPY-immunoreactive cells were found among the lining epithelial cells of the bile ducts in the interlobular septum.
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PMID:Peptidergic innervation and endocrine cells in the human liver. 769 56

Primary human neoplasms were examined for the presence of substance-P receptors by receptor autoradiography with 125I-labelled Bolton-Hunter substance P. Substance-P receptors were localized and characterized in the neoplastic cells of 9/12 astrocytomas, 10/10 glioblastomas, 10/12 medullary thyroid carcinomas, 8/16 breast carcinomas and 4/5 ganglioneuroblastomas. Conversely, substance-P receptors were not or only rarely identified on non-small-cell carcinomas of the lung (1/16), neuroblastomas (0/8), adenocarcinomas of the colon (1/21) or the pancreas (1/9), or on malignant lymphomas (3/18). However, in the great majority of the investigated tumours, substance-P receptors were found on intra- and peritumoral blood vessels. All substance-P receptors detected had the pharmacological characteristics of the neurokinin-I receptor sub-type. In addition, the expression of somatostatin receptors was examined in all the neoplastic tissues mentioned above. Both substance-P and somatostatin receptors were present in astrocytomas and in ganglioneuroblastomas, whereas little or no receptor was found in pancreatic and non-small-cell lung carcinomas. The extent of somatostatin-receptor expression was inversely correlated to that of the substance-P receptors in glioblastomas, neuroblastomas and non-Hodgkin's lymphomas. The tumoral and vascular localization of substance-P receptors in tumours may have clinical implications. The use of radiolabelled substance P for in vivo scintigraphy may supplement the current set of diagnostic tools. Substance-P antagonists might be used in the treatment of tumours, as their binding to vascular receptors may decrease tumoral blood supply and drainage.
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PMID:Substance-P receptors in human primary neoplasms: tumoral and vascular localization. 779 Jan 12

Endothelium-derived hyperpolarizing factor (EDHF)-attributed hyperpolarizations and relaxations were recorded simultaneously from submucosal arterioles of guinea pigs with the use of intracellular microelectrodes and a video-based system, respectively. Membrane currents were recorded from electrically short segments of arterioles under single-electrode voltage clamp. Substance P evoked an outward current with a current-voltage relationship that was well described by the Goldman-Hodgkin-Katz equation for a K+ current, consistent with the involvement of intermediate- and small-conductance Ca2+-activated K+ channels. 1-Ethyl-2-benzimidazolinone relaxed the arterioles and evoked hyperpolarizations that were blocked by charybdotoxin, but not by iberiotoxin. Application of K+ induced depolarization under conditions in which EDHF evoked hyperpolarization. The Ba2+-sensitive component of the K+-induced current was inwardly rectifying, in contrast to the outwardly rectifying current evoked by substance P. EDHF-attributed hyperpolarizations in dye-identified smooth muscle cells were indistinguishable from those recorded from dye-identified endothelial cells in the same arterioles. These results provide evidence that EDHF is not K+ but may involve electrotonic spread of hyperpolarization from the endothelial cells to the smooth muscle cells.
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PMID:EDHF is not K+ but may be due to spread of current from the endothelium in guinea pig arterioles. 1135 1

Exchange of information occurs between cells of neuroendocrine and immune systems. Neuroendocrine hormones may modulate lymphoid cell activities, including proliferation and mitogenesis, and immune cells may produce neuropeptides as well. Neuropetide Y is synthesized in B-cell leukaemia lymphoblasts, while substance P immunoreactivity has been detected in neoplastic haematological samples of different types of leukaemias. The presence of receptors for neuropeptides on different animal and human lymphoid cell lines, as well as in several types of animal and human lymphoproliferative diseases has been demonstrated. Species variability in receptor distribution has been shown as well. Receptor expression in immune cells may be regulated by changes in microenvironmental conditions, it may also be related to the activation and/ or proliferation state of cells. Vasoactive intestinal peptides receptors have been detected in myeloma cells, while somatostatin receptors have been first detected in vitro on resting lymphocytes and cells of the monocyte/macrophage lineage, and later on human activated lymphocytes and on lymphoblastic leukaemia cells. Somatostatin receptors have been found in biopsies from patients with malignant lymphomas. Tumor localization in non-Hodgkin lymphomas and Hodgkin's disease can be visualized by in vivo somatostatin receptor scintigraphy, contributing to establish the diagnosis and the stage of the disease. Recently. somatostatin receptors have been in vivo and in vitro detected in human thymic tumors. Although treatment of lymphoproliferative diseases with somatostatin analogs is a little explored field, partial remission was found in patients with low-grade non-Hodgkin lymphoma and cutaneous T-cell lymphoma, and a successful treatment with octreotide has been reported in patients with thymoma. Specific somatostatin receptors present in progenitors of immune cells are not expressed in the mature phenotype, while they can be detected in transformed cell lines. The possibility that this phenomenon is caused by oncogene expression cannot be ruled out. Moreover, preliminary data showed a developmental expression of somatostatin receptors in lymphoid cells, suggesting a potential role for neuropeptide receptors as differentiation markers. Although controlled studies are warranted to investigate the efficacy of the currently available analogs, somatostatinergic compounds may be of interest in the treatment of lymphoproliferative malignancies. A promising approach in refractory patients with somatostatin receptor positive malignant lymphomas may be radionuclide-targeted and cytotoxic analog therapy. These concepts increase the possibility of a wider antitumor treatment with ligands for neuroepeptide receptors than in established 'classic' neuroendocrine tumors.
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PMID:Neuroendocrine aspects of immunolymphoproliferative diseases. 1176 38