(n.) One who contends with another, especially in combat; an adversary; an opponent.
(n.) A muscle which acts in opposition to another; as a flexor, which bends a part, is the antagonist of an extensor, which extends it.
(n.) A medicine which opposes the action of another medicine or of a poison when absorbed into the blood or tissues.
(a.) Antagonistic; opposing; counteracting; as, antagonist schools of philosophy.
Example Sentences:
(1) This death is also dependent on the presence of chloride and is prevented with the non-selective EAA antagonist, kynurenic acid, but is not prevented by QA.
(2) Microionophoretically applied excitatory amino acids induced firing of extracellularly recorded single units in a tissue slice preparation of the mouse cochlear nucleus, and the similarly applied antagonist 2-amino-5-phosphonovalerate (2APV) was demonstrated to be a selective N-methyl-D-aspartate (NMDA) receptor antagonist.
(3) Meanwhile the efficiency of muscarinic antagonists in inhibition of tremor reaction induced by arecoline administration is associated with interaction between the drugs and the M2-subtype.
(4) The anticonvulsant properties of the endogenous excitatory amino acid antagonist, kynurenic acid (KYA), were studied in prepubescent and adult rats using the amygdaloid kindling model of epilepsy.
(5) A novel bicyclic prostaglandin analogue, (1S)-[1 alpha,2 alpha(Z),3 alpha,4 alpha]-7-[3-[(hexylthio)methyl]-7- oxabicyclo [2.2.1]hept-2-yl]-5-heptenoic acid ((-)-10), and its cogeners were found to be potent antagonists at the TxA2 receptor.
(6) This difference was abolished by exposure of the slices to propranolol, a beta-adrenergic receptor antagonist.
(7) The TxA2 antagonistic effects of KW-3635 were compared with that of daltroban in PRP from various animals species.
(8) In experiments performed to determine whether PtdIns(4,5)P2 hydrolysis induced by TRH may have been caused by the elevation of [Ca2+]i, the following results were obtained: the effect of TRH to decrease the level of PtdIns(4,5)P2 was not reproduced by the calcium ionophore A23187 or by membrane depolarization with 50 mM K+; the calcium antagonist TMB-8 did not inhibit the TRH-induced decrease in PtdIns(4,5)P2; and, most importantly, inhibition by EGTA of the elevation of [Ca2+]i did not inhibit the TRH-induced decrease in PtdIns(4,5)P2.
(9) Similarly, 50 microM D-600, a Ca+2 channel antagonist, significantly (P less than 0.01) reduced basal and 5-HETE-induced PRL release.
(10) Selective removal of endothelium had no effect on BK-induced contraction or the action of the antagonists.
(11) The second experiments entailed use of the nonspecific opiate antagonist, naloxone, as well as the specific delta antagonist, ICI 154,129, against seizures induced by icv-administered morphine, morphiceptin, DADL, or DSLET.
(12) These antagonists reverse NMDA-mediated long term influence in these brain areas.
(13) This novel mechanism of receptor regulation, named transmodulation, should be distinguished from the reduction in total receptor number caused by the homologous ligand (downregulation) and from the change in affinity produced by the binding of agonists or antagonists to the same receptor site.
(14) Furthermore, the ability of a vasopressin antagonist to lower arterial pressure in NTS hypertensive rats was markedly attenuated by clonidine treatment.
(15) All of the serotonergic antagonists studied had additional effects on the response of the coronary artery to electrical stimulation or to norepinephrine.
(16) Their receptive fields comprise a temporally and spatially linear mechanism (center plus antagonistic surround) that responds to relatively low spatial frequency stimuli, and a temporally nonlinear mechanism, coextensive with the linear mechanism, that--though broad in extent--responds best to high spatial-frequency stimuli.
(17) The effects of low doses of dihydropyridine (DHP) calcium channel antagonists nimodipine, nifedipine, (-)-R-202-791, and amlodipine, the DHP calcium channel agonist BAY K 8644 were investigated on clonic convulsions to pentylenetetrazole (PTZ) in mice.
(18) Addition in the cultures of 4-deoxypyridoxine, a potent antagonist of vitamin B6 coenzymes, concurrently with the mitogen, inhibits the induction of serine hydroxymethyltransferase.
(19) These results suggest that prevention of xenograft rejection using PAF-antagonist in association with other methods should be further investigated.
(20) The high concentrations of gonadotropins present in immature female rats by the end of the second week of life were suppressed by treatment with an antagonist against luteinizing hormone-releasing hormone (LHRH-A; Org.
Catalyst
Definition:
Example Sentences:
(1) The radioprotective action in E. coli ATCC 9637 of ascorbate added to media containing the weak sensitizer, tetracycline (effect described by Pittillo and Lucas (1967)), was found to be dependent on the presence of metal catalysts of the autoxidation of ascorbate.
(2) "If I hadn't scored that goal, I might still have ended up playing in Italy [Platt went on to play for Bari, Juventus and Sampdoria] but, realistically, I'm sure it was the catalyst.
(3) Enzymes are good catalysts in terms of high catalytic and specific activity with ability to function under mild conditions.
(4) The main aim of this brief contribution is to suggest that our understanding of the general principles of osmochemistry may provide useful insights into the type of mechanism by which solute-translocating catalysts work.
(5) Shelby Quast, of Equality Now, said the gathering could be a “tipping point” and act as a catalyst for change, so that girls in the US could finally be protected: “It’s the first time that members of the government are coming around the table to meet with civil society, survivors and members of the diaspora – this is the first step towards putting together a comprehensive action plan to tackling FGM.” Campaigners are calling for the government to look at practical ways that FGM could be wiped out in the United States – such as engaging with paediatricians and other doctors, immigration officers and visa offices.
(6) With different oxidation catalysts most antioxidants and amino acids tested enhanced polymerization.
(7) The high sites' density with basic character, evidenced by use of various probe molecules, is very similar for the two asbestos types (chrysotile and crocidolite) and on the same order as the density encountered in some catalysts.
(8) Fillings were made of Concise composite resin, without applying an intermediary resin (1), after applying the resin layer (2), after diluting the mix with one (3) or two (4) drops of catalyst resin but without an intermediary resin, and after diluting the mix and applying the resin layer (5).
(9) Monoclonal antibodies elicited to haptens that are analogs of the transition state for hydrolysis of carboxylic esters behaved as enzymic catalysts with the appropriate substrates.
(10) Rapid addition of purines and pyrimidines to alpha, beta-unsaturated carbonyl compounds (such as acrolin) is a general phenomenon which does not require an amine catalyst.
(11) Time acts as a catalyst for members to learn to respect and appreciate each other.
(12) The resulting solution is directed into tubes containing a catalyst that is activated by UV light and causes the dissolved CO2 to react with water (H2O) to form methanol (CH3OH).
(13) Manganese therefore acts as a catalyst for the non-enzymatic reaction, but magnesium does not.
(14) When the reaction was done in dimethyl sulfoxide, with 1-methylimidazole as the catalyst, a third compound was observed, and identified as 1,2,4-tri-O-acetyl-3-C-(acetoxymethyl)-3-O-(methylthiomethyl)-D-glycero- tetrito l [3-O-(methylthiomethyl)apiitol tetraacetate] by gas-liquid chromatography and mass spectrometry.
(15) Russell also described the Commonwealth Games as a catalyst but was realistic enough not to claim they immediately changed an area with long, deep-rooted problems, or miraculously roused a poor, generally unhealthy local population into vigorously playing sport.
(16) The device limits the amount of oxygen entering with the sample to a maximum of 2%, which is rapidly removed by reacting with hydrogen in the presence of a palladium catalyst.
(17) The yields of Thf-FU and more especially of Thf2-FU were greatly dependent on the relative amount of SnCl4, and 0.01-0.1 equiv of the catalyst with respect to Me3Si-FU gave the best results.
(18) Some officers close to the case believe George and Allen may have always harboured paedophilic thoughts but Blanchard provided a "catalyst" which encouraged them to act out their fantasies.
(19) Dusan Tadic was introduced at the break and looked a catalyst for a comeback.
(20) These findings may indicate that trace amounts of acidic catalysts remaining after production of IPM are responsible for the toxic effect.