Search results for "Receptor"
showing 10 items of 6990 documents
In vivo antihypertensive mechanism of lactoferrin-derived peptides: Reversion of angiotensin I- and angiotensin II-induced hypertension in Wistar rats
2015
Novel peptides with antihypertensive effects in SHR rats have previously been identified in lactoferrin (LF) hydrolysates. To investigate their in vivo antihypertensive mechanism, we have assessed the blood pressure lowering effects of two of these LF-derived peptides (RPYL and DPYKLRP) in Wistar rats subjected to either angiotensin I- or angiotensin II-induced hypertension. Blood pressure was measured by the tail-cuff method, hypertension was induced by subcutaneous infusion of angiotensins, and then captopril, valsartan or LF-derived peptides orally administered. Angiotensin I- and angiotensin II-induced hypertension were reversed by captopril and valsartan, respectively. RPYL and DPYKLRP…
The deubiquitinating enzyme CYLD regulates the differentiation and maturation of thymic medullary epithelial cells.
2014
The cross talk between thymocytes and the thymic epithelium is critical for T-cell development and the establishment of central tolerance. Medullary thymic epithelial cells (mTECs) are located in the thymic medulla and mediate the elimination of self-reactive thymocytes, thereby preventing the onset of autoimmunity. Previous studies identified the deubiquitinating enzyme CYLD as a critical regulator of T-cell development by activating proximal T-cell receptor signaling during the transition of double-positive to single-positive thymocytes. Here we evaluated the impact of the naturally occurring short-splice variant of the cyld gene (sCYLD) on the development and maturation of mTECs. We foun…
Pharmacological Characterization of Loss of Function Mutations of the Human Melanocortin 1 Receptor That Are Associated with Red Hair
2004
Variation in skin color is the major host risk factor for melanoma and other forms of skin cancer. Individuals with red hair show an increased ratio of phaeomelanin to eumelanin in both hair and skin. This ratio is regulated by the melanocortin (MC) 1 receptor. There are several common point mutations in the human MC1 receptor that are overrepresented in North European red-heads, and in individuals with pale skin. In order to determine the functional significance of these mutations, we expressed the Asp84Glu, Val92Met, Arg163Gln, and Asp294His variants of the human MC1 receptors in eukaryotic cells and determined their ability to bind alpha-melanocyte stimulating hormone (MSH) peptides and …
Embryonic and foetal Islet-1 positive cells in human hearts are also positive to c-Kit.
2011
During embryogenesis, the mammalian heart develops from a primitive heart tube originating from two bilateral primary heart fields located in the lateral plate mesoderm. Cells belongings to the pre-cardiac mesoderm will differentiate into early cardiac progenitors, which express early transcription factors which are also common to the Isl-1 positive cardiac progenitor cells isolated from the developing pharyngeal mesoderm and the foetal and post-natal mice hearts. A second population of cardiac progenitor cells positive to c-Kit has been abundantly isolated from adult hearts. Until now, these two populations have been considered two different sets of progenitor cells present in the heart in…
Metabolic changes in the rat liver during pregnancy
1983
During pregnancy the rat liver shows alterations in metabolism which apparently do not to occur in the non-pregnant animal. In our study, the following metabolite concentrations and enzyme activities in the liver of pregnant and non-pregnant rats were measured after fasting periods of 6 and 12 h: malate, fumarate, isocitrate, alpha-keto-glutarate, glutamate, malate-dehydrogenase, fumarate-hydratase, glutamate-dehydrogenase, isocitrate-dehydrogenase, aspartate-aminotransferase and after 12 h fast, the concentrations of acetyl coenzyme A and citrate. These results are discussed with regard to their possible importance for the maternal and fetal energy supply.
Exploring gastric emptying rate in minipigs: Effect of food type and pre-dosing of metoclopramide.
2018
The present study investigated the gastric emptying rate in Gottingen minipigs pre- and post-prandial and evaluated the effect of metoclopramide on the same parameter, using paracetamol as an absorption marker. The pharmacokinetic evaluation of the obtained plasma concentration data for paracetamol demonstrated that the fastest gastric emptying rate was observed in the animals that were allowed access to normal pig food. There was no significant difference in the stomach emptying rate observed between fasted and fed minipigs, when fed either with a FDA standard breakfast or a nutritional energy drink. Pre-dosing minipigs with metoclopramide (0.2 or 0.4 mg/kg) did not demonstrate any effect …
Stabilization of Perivascular Mast Cells by Endothelial CNP (C-Type Natriuretic Peptide)
2020
Objective: Activated perivascular mast cells (MCs) participate in different cardiovascular diseases. Many factors provoking MC degranulation have been described, while physiological counterregulators are barely known. Endothelial CNP (C-type natriuretic peptide) participates in the maintenance of vascular barrier integrity, but the target cells and mechanisms are unclear. Here, we studied whether MCs are regulated by CNP. Approach and Results: In cultured human and murine MCs, CNP activated its specific GC (guanylyl cyclase)-B receptor and cyclic GMP signaling. This enhanced cyclic GMP–dependent phosphorylation of the cytoskeleton-associated VASP (vasodilator-stimulated phosphoprotein) and…
An O2-sensitive glomus cell-stem cell synapse induces carotid body growth in chronic hypoxia.
2013
Summary Neural stem cells (NSCs) exist in germinal centers of the adult brain and in the carotid body (CB), an oxygen-sensing organ that grows under chronic hypoxemia. How stem cell lineage differentiation into mature glomus cells is coupled with changes in physiological demand is poorly understood. Here, we show that hypoxia does not affect CB NSC proliferation directly. Rather, mature glomus cells expressing endothelin-1, the O 2 -sensing elements in the CB that secrete neurotransmitters in response to hypoxia, establish abundant synaptic-like contacts with stem cells, which express endothelin receptors, and instruct their growth. Inhibition of glomus cell transmitter release or their sel…
Hepatocellular Hyperplasia, Plasmacytoma Formation, and Extramedullary Hematopoiesis in Interleukin (IL)-6/Soluble IL-6 Receptor Double-Transgenic Mi…
1998
Cytokines interact not only with membrane anchored receptors, but also with specific soluble receptors which circulate in the bloodstream. In general, soluble cytokine receptors such as soluble tumor necrosis factor receptor, soluble interleukin 1 receptor, and soluble interleukin 4 receptor compete with their membrane-bound counterparts for the ligands and therefore act as antagonists. In contrast, soluble receptors for cytokines of the interleukin-6 (IL-6) family complex with their ligands act agonistically. Interestingly, the complex of IL-6 and the soluble interleukin 6 receptor (sIL-6R) activates target cells that do not express the membrane-bound IL-6R and therefore cannot respond to …
PGC-1α: a master gene that is hard to master
2012
Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a transcriptional coactivator that favorably affects mitochondrial function. This concept is supported by an increasing amount of data including studies in PGC-1α gene-deleted mice, suggesting that PGC-1α is a rescue factor capable of boosting cell metabolism and promoting cell survival. However, this view has now been called into question by a recent study showing that adeno-associated virus-mediated PGC-1α overexpression causes overt cell degeneration in dopaminergic neurons. How is this to be understood, and can these seemingly conflicting findings tell us something about the role of PGC-1α in cell stress and in cont…