| HF | Hageman factor; haplotype frequency; hard filled [capsule]; hay fever; head of fetus; head forward; ... |
|---|---|
| IF | idiopathic fibroplasia; idiopathic flushing; immersion foot; immunofluorescence; indirect fluorescen... |
| KAF | conglutinogen-activating factor; killer-assisting factor; kinase activating factor |
| LEF | leukokinesis-enhancing factor; lupus erythematosus factor; lymphoid-enhanced binding factor |
| LIF | laser-induced fluorescence; left iliac fossa; left index finger; leukemia-inhibiting factor; leukocy... |
| receptors, vasoactive intestinal peptide | Cell surface proteins that bind vasoactive intestinal peptide (vip) with high affinity and trigger intracellular changes which influence the behaviour of cells. (12 Dec 1998) |
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| receptors, vasopressin | Specific molecular sites or structures on or in cells that vasopressins react or to which they bind in order to modify the function of the cells. Two types of vasopressin receptor exist, the v1 receptor and the v2 receptor. The v1 receptor can be subdivided into v1a and v1b (formerly v3) receptors. (12 Dec 1998) |
| receptors, very late antigen | Members of the integrin family appearing late after T-cell activation. They are a family of proteins initially identified at the surface of stimulated T-cells, but now identified on a variety of cell types. At least six vla antigens have been identified as heterodimeric adhesion receptors consisting of a single common beta-subunit and different alpha-subunits. (12 Dec 1998) |
| receptors, virus | Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response. (12 Dec 1998) |
| receptors, vitronectin | Alpha-v beta-3 integrins that bind vitronectin with high affinity and play a role in cell migration. They also bind fibrinogen, von willebrand factor, osteopontin, and thrombospondin. The highly homologous alpha-v beta-5 integrin also binds vitronectin, but mediates simple adhesion. (12 Dec 1998) |
| cholinergic receptors | Chemical sites in effector cells or at synapses through which acetylcholine exerts its action. (05 Mar 2000) |
| muscarinic receptors | Membrane-bound proteins whose extracellular domain contains a recognition site for acetylcholine (ACh); combination of Ach with the receptor initiates a physiologic change (slowing of heart rate, increased glandular secretory activity and stimulation of smooth muscle contractions); changes are observed after treatment with the mushroom alkaloid, muscarine. Muscarinic receptors are to be distinguished from nicotinic receptors. (05 Mar 2000) |
| saturation of receptors | Saturation, the state in which all receptors are effectively occupied all the time, can be said to occur in a simple binding equilibrium when the concentration of ligand is more than 5 times the Kd value, although strictly this will only be true at infinite ligand concentration. (18 Nov 1997) |
| pulmonary stretch receptors | Stretch receptors found in the bronchi and bronchioles. Pulmonary stretch receptors are sensors for a reflex which stops inspiration. In humans, the reflex is protective and is probably not activated during normal respiration. (12 Dec 1998) |
| sensory receptors | Peripheral endings of afferent neurons. (05 Mar 2000) |
| stretch receptors | Receptor's that are sensitive to elongation, especially those in Golgi tendon organs and muscle spindles, but also those found in visceral organs such as the stomach, small intestine, and urinary bladder; these receptor's have the function of detecting elongation, and this distinguishes them from baroreceptors, which actually are activated by stretching of the wall of the blood vessel but whose function is to elicit central reflex mechanism reducing the arterial blood pressure. (05 Mar 2000) |
| nicotinic receptors | A class of cholinergic receptors on skeletal muscle cells that are linked to ion channels in the cell membrane. (05 Mar 2000) |
| opiate receptors | Regions of the brain which have the capacity to bind morphine; some, along the aqueduct of Sylvius and in the centre median, are in areas related to pain, but others, as in the striatum, are not related. (05 Mar 2000) |
| T-cell antigen receptors | Receptors present on T-cells that interact with both processed antigen and major histocompatibility antigens simultaneously. (05 Mar 2000) |
| Fc receptors | <immunology> Receptors for the Fc portion of immunoglobulins. Fc_R (30 kD) is the receptor for serum and secretory IgA1 or IgA2 and is expressed on most myeloid cells and subpopulations of T and B-cells. Fc_RI (CD64) High affinity receptor (72 kD on gels) for monomeric IgG1 found on monocytes, macrophages and some neutrophils. The extracellular portion has three immunoglobulin superfamily C2 domains, in contrast to Fc_RII, Fc_RIII that have only two. Involved in antibody dependent cell killing and in clearance of immune complexes. Fc_RII (CD32) Low affinity receptor 40 kD) for aggregated IgG that exists in several sub types coded by three closely related genes, A, B and C. All forms are found on monocytes, the B forms (that are alternatively spliced) are found on B-cells, the A and C forms are present on neutrophils. Binding of aggregated IgG will trigger phagocytosis and the oxidative burst in neutrophils. Fc_RIII (CD16) is the low affinity receptor (50-80 kD on gels) for aggregated IgG. It is found in transmembrane and GPI linked forms. The transmembrane form associates with the _ subunit of Fc_RI or the TCR_ chain and on B-cells with the _ chain of Fc_RI. Has structural similarity with Fc_RI, Fc_RII and Fc_RI_. Binding of aggregated IgG or IgG antigen complexes mediates phagocytosis or antibody dependent cellular cytotoxicity. Fc_RI is a heteromeric high affinity receptor for IgE found on mast cells and basophils. The _ chain (45-65 kD on gels, 25 kD of polypetide) is N glycosylated and has two immunoglobulin C2 loops in addition to the transmembrane domain, the _ chain (32 kD) has four transmembrane domains, the _ subunit is a homodimer (8 kD monomer) identical to the _ subunit of CD16 and has similarity with _ and _ chains associated with the T-cell receptor. Binding of antigen to the IgE Fc_R complex triggers the release of histamine and various inflammatory mediators. Fc_RIIa & b CD23) Low affinity receptor (45 kD) for IgE. Both a and b are present on mature B-cells, the b form on monocytes, IL-4 activated macrophages, eosinophils, platelets and dendritic cells. The protein has a C type lectin domain that mediates IgE binding and can be cleaved from the membrane to yield an active soluble form. (18 Nov 1997) |