Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neurons containing neural nitric oxide synthase (nNOS) are found in various locations in the hypothalamus and, in particular, in the paraventricular and supraoptic nuclei with axons which project to the median eminence and extend into the neural lobe where the highest concentrations of NOS are found in the rat. Furthermore, nNOS is also located in folliculostellate cells and LH gonadotropes in the anterior pituitary gland. To define the role of NO in the release of hypothalamic peptides and pituitary hormones, we injected an inhibitor of NOS, Ng-monomethyl-L-arginine (NMMA) or a releasor of NO, nitroprusside (NP) into the third ventricle (3V) of conscious castrate rats and determined the effect on the release of various pituitary hormones. In vitro, we incubated medial basal hypothalamic (MBH) fragments and studied inhibitors of NO synthase and also releasors of NO. The results indicate that NOergic neurons play an important role in stimulating the release of corticotrophin-releasing hormone (CRH), luteinizing hormone releasing-hormone (LHRH), prolactin-RH's, particularly oxytocin, growth hormone-RH (GHRH) and somatostatin, but not FSH-releasing factor from the hypothalamus. NO stimulates the release of LHRH, which induces sexual behavior, and causes release of LH from the pituitary gland. The intrahypothalamic pathway by which NO controls LHRH release is as follows: glutamergic neurons synapse with noradrenergic terminals in the MBH which release nonepinephrine (NE) that acts on alpha 1 receptors on the NOergic neuron to increase intracellular free Ca++ which combines with calmodulin to activate NOS. The NOS diffuses to the LHRH terminal and activates guanylate cyclase (GC), cyclooxygenase and lipoxygenase causing release of LHRH via release of cyclic GMP, PGE2 and leukotrienes, respectively. Alcohol and cytokines can block LHRH release by blocking the activation of cyclooxygenase and lipoxygenase without interfering with the activation of GC. GABA also blocks the response of the LHRH neurons to NO and recent experiments indicate that granulocyte macrophage colony-stimulating factor (GMCSF) blocks the response of the LHRH neuron to NP by activation of GABA neurons since the blockade can be reversed by the competitive inhibitor of GABAa receptors, bicuculine.
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PMID:The role of nitric oxide (NO) in control of hypothalamic-pituitary function. 939 93

The thymus provides an optimal humoral microenvironment for the development of immunocompetent T cells. Although yolk sac derived pre-T, committed hematopoietic stem cells enter the thymus using a homing receptor, the immigration process also requires secretion of a peptide called thymotaxin by the cells of the reticulo-epithelial (RE) network of the thymic cellular microenvironment. The majority of RE cells have a round or irregular pale nucleus, which contains few, scattered, chromatin granules with a defined, spherical nucleolus, rich in basic histones. Their cytoplasm occasionally displays RNP granules, and is rich in non-histone proteins, fine phospholipid, lipid or cholesterin granules, and vacuoles filled with secreted substances. The cells of the subcapsular, endocrine RE cell layer (giant or nurse cells), characterized by PAS positive granules, express A2B5/TE4 cell surface antigens and MHC Class I (HLA A, B, C) molecules. In contrast to medullar RE cells, these subcapsular nurse cells also produce thymosins beta 3 beta 4. Thymic nurse cells (TNCs) display a neuroendocrine cell specific immunophenotype (IP): Thy-1+, A2B5+, TT+, TE4+, UJ13/A+, UJ127.11+, UJ167.11+, UJ181.4+, and presence of common leukocyte antigen (CLA+). Medullar RE cells display MHC Class II (HLA-DP, HLA-DQ, HLA-DR) molecule restriction. These cells also contain transforming growth factor-beta (TGF-beta) type II receptors and participate in the positive selection of T cells. Transmission electron-microscopic (TEM) observations have defined four functional subtypes of medullar RE cells: undifferentiated, squamous, villous, and cystic. All subtypes are connected by desmosomes. Immunocytochemical observations have shown that the secreted thymic hormones, thymosin alpha 1 and thymopoietin (and its short form, thymopentin or TP5), are produced by the same RE cells. Thymic RE cells also produce numerous cytokines including IL1, IL6, G-CSF, M-CSF, and GM-CSF that likely are important in various stages of thymocyte activation and differentiation. The co-existence of pituitary hormone and neuropeptide secretion, such as growth hormone, prolactin, adrenocorticotropic hormone, thyroid stimulating hormone, triiodothyronine, somatostatin, oxytocin, follicle stimulating hormone, luteinizing hormone, arginine vasopressin, growth hormone releasing hormone, corticotropin releasing hormone, nerve growth factor, vasoactive intestinal peptide, (pro) enkephalin, and beta-endorphin, production of a number of interleukins and growth factors, as well as the expression of receptors for all, by the same RE cell is an unique molecular biological phenomenon. These data illustrate the immensely important and diverse immuno-neuroendocrine functions of the thymic RE cellular network. Based on our systematic observations of the thymus in humans and other mammalian species, we suggest that the thymic RE cell network represents an extremely important cellular and humoral microenvironment in homeopathic regulatory mechanisms of the multicellular organism. Intrathymic T lymphocyte selection is a complex, multistep process, influenced by several functionally specialized RE cell subtypes and under constant immuno-neuroendocrine regulation, reflecting the dynamic changes of the organism.
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PMID:Molecular biological ontogenesis of the thymic reticulo-epithelial cell network during the organization of the cellular microenvironment. 1045 6

The thyrnus provides an optimal cellular and humoral microenvironment for the development of immunocompetent T lymphocytes. Although yolk sac derived pre-T, committed hematopoietic stem cells enter the thymus using a homing receptor, the immigration process also requires secretion of a peptide, called thymotaxin by the cells of the reticulo-epithelial (RE) network of the thymic cellular microenvironment. The thymic RE cells are functionally specialized based on their location within the thymic microenvironment. Thus, although subcapsular, cortical, and medullary RE cells are derived from a common, endodermal in origin epithelial precursor cell, their unique location within the gland causes their specialization in terms of their immunophenotypical and in situ physiological properties. The subcapsular, endocrine, RE cell layer (giant or nurse cells) is comprised of cells filled with PAS positive granules, which also express A2B5/TE4 cell surface antigens and MHC Class I (HLA A, B, C) molecules. In contrast to the medullary RE cells, these subcapsular nurse cells also produce thymosins beta 3 and beta 4. The thymic nurse cells (TNCs) display a neuroendocrine cell specific immunophenotype (IP): Thy-1+, A2B5+, TT+, TE4+, UJ13/A+, UJ127.11+, UJ167.11+, UJ181.4+, and presence of common leukocyte antigen (CLA+). Medullar RE cells display MHC Class II (HLA-DP, HLA-DQ, HLA- DR) molecule restriction. These cells also contain transforming growth factor (TGF)-beta type II receptors and are involved in the positive selection of T cells. Transmission electronmicroscopic (TEM) observations have defined four, functional subtypes of medullary RE cells: undifferentiated squamous, villous and cystic. All subtypes were connected with desmosomes. The secreted thy nic hormones, thymulin, thymosin-alpha 1 and thymopoietin (its short form, thymopentin or TP5) were detected immunocytochemically to be produced by RE cells. Thymic RE cells also produce numerous cytokines including IL-1, IL-6, G-CSF, M-CSF, and GM-CSF molecules that likely are important in various stages of thymocyte activation and differentiation. The co-existence of pituitary hormone and neuropeptide secretion [growth hormone (GH), prolactin (PRL), adrenocorticotropic hormone (ACTH), thyroid stimulating hormone (TSH), triiodothyronine (T3), somatostatin, oxytocin (OT), follicle stimulating hormone (FSH), luteinizing hormone (LH), arginine vasopressin (AVP), growth hormone releasing hormone (GHRH), corticotropin releasing hormone (CRH), nerve growth factor (NGF), vasoactive intestinal peptide (VIP), pro-enkephalin (pro-enk), and beta-endorphin (beta-end)], as well as production of a number of interleukins and growth factors and expression of receptors for all, by RE cells is an unique molecular biological phenomenon. The thymic RE cell network is most probably comprised of cells organized into sub-networks--functional units composed of RE cells with differing hormone production/hormone receptor expression profiles, involved in the various stages of T lymphocyte maturation. Furthermore, it is quite possible that even on the level of individual RE cells, the numerous projections associated with a single cell, which engulf developing lymphocytes, nurturing and guiding them in their maturation, may differ in their hormone production and/or hormone receptor expression profile, thus allowing a single cell to be involved in distinct, separate steps of the T cell maturation process. Based on our systematic observations of the thymus in humans and other mammalian species, we suggest that the thymic RE cells represent an extremely important cellular and humoral network within the thymic microenvironment and are involved in the homeopathic regulation mechanisms of the multicellular organism, in addition to the presentation of various antigens to developing lymphocytes, and providing growth regulatory signals which may range from stimulatory to apoptotic signaling within the thymus. (ABSTRACT TRUNCA
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PMID:The role of the reticulo-epithelial (RE) cell network in the immuno-neuroendocrine regulation of intrathymic lymphopoiesis. 1092 21