| OCS | occipital condyle syndrome; Ondine's curse syndrome; open canalicular system; oral contraceptive ste... |
|---|---|
| OCT | object classification test; optimal cutting temperature; oral contraceptive therapy; ornithine carba... |
| OES | oral esophageal stethoscope; optical emission spectroscopy |
| OGTT | oral glucose tolerance test |
| OHA | oral hypoglycemic agents |
| sodium channel | <neurology, physiology> The protein responsible for electrical excitability of neurons. A transmembrane ion channel, containing an aqueous pore around 0.4nm diameter, with a negatively charged region internally (the selectivity filter) to block passage of anions. The channel is voltage gated: it opens in response to a small depolarisation of the cell (usually caused by an approaching action potential), by a multistep process. Around 1000 sodium ions pass in the next millisecond, before the channel spontaneously closes (an event with single step kinetics). The channel is then refractory to further depolarisations until returned to near the resting potential. There are around 100 channels per square micron in unmyelinated axons, in myelinated axons, they are concentrated at the nodes of Ranvier. The sodium channel is the target of many of the deadliest neurotoxins. (18 Nov 1997) |
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| sodium channels | Cell membrane glycoproteins selective for sodium ions. Fast sodium current is associated with the action potential in neural membranes. (12 Dec 1998) |
| sodium chloride | <chemical> Table salt, NaCL. (09 Oct 1997) |
| sodium chloride, dietary | Sodium chloride used in foods. (12 Dec 1998) |
| sodium citrate | Na3C6H5O7 -2H2O; trisodium citrate;used as diuretic, antilithic, systemic and urinary alkaliser, expectorant, and anticoagulant (in vitro). Synonym: sodium acid citrate. (05 Mar 2000) |
| sodium citrate acid | C6H6O7Na-11/2H2O; disodium hydrogen citrate;same actions and uses as sodium citrate; in addition, it may be used in solutions of glucose without producing caramelization of the latter during autoclaving. (05 Mar 2000) |
| sodium compounds | Inorganic compounds that contain sodium as an integral part of the molecule. (12 Dec 1998) |
| sodium cromoglycate | <chemical> A chromone complex that acts by inhibiting the release of chemical mediators from sensitised mast cells. It is used in the prophylactic treatment of both allergic and exercise-induced asthma, but does not affect an established asthmatic attack. Pharmacological action: anti-asthmatic agents. Chemical name: 4H-1-Benzopyran-2-carboxylic acid, 5,5'-((2-hydroxy-1,3-propanediyl)bis(oxy))bis(4-oxo-, disodium salt (12 Dec 1998) |
| sodium cyanide | <chemical> Sodium cyanide (na(cn)). A highly poisonous compound that is an inhibitor of many metabolic processes and is used as a test reagent for the function of chemoreceptors. It is also used in many industrial processes. Pharmacological action: enzyme inhibitors, indicators and reagents, poisons. Chemical name: Sodium cyanide (Na(CN)) (12 Dec 1998) |
| sodium dehydrocholate | A cholagogue; also used to determine circulation time. (05 Mar 2000) |
| sodium diatrizoate | A water-soluble organic iodine compound formerly used for intravenous excretory urography and angiography. (05 Mar 2000) |
| sodium, dietary | Sodium or sodium compounds used in foods or as a food. The most frequently used compounds are sodium chloride or sodium glutamate. (12 Dec 1998) |
| sodium dihydrogen phosphate | NaH2PO4-H2O;used to increase urinary acidity. Synonym: primary sodium phosphate, sodium acid phosphate, sodium dihydrogen phosphate. (05 Mar 2000) |
| sodium dimethylarsenate | (CH3)2AsOONa-3H2O;used in anaemia, leukaemia, and malaria. Synonym: sodium dimethylarsenate. (05 Mar 2000) |
| sodium dodecyl sulfate | <chemical> An anionic surfactant, usually a mixture of sodium alkyl sulfates, mainly the lauryl; lowers surface tension of aqueous solutions; used as fat emulsifier, wetting agent, detergent in cosmetics, pharmaceuticals and toothpastes; also as research tool in protein biochemistry. Pharmacological action: surface-active agent. Chemical name: Sulfuric acid monododecyl ester sodium salt (12 Dec 1998) |