(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.
Physiological
Definition:
(a.) Of or pertaining to physiology; relating to the science of the functions of living organism; as, physiological botany or chemistry.
Example Sentences:
(1) We have investigated a physiological role of endogenous insulin on exocrine pancreatic secretion stimulated by a liquid meal as well as exogenous secretin and cholecystokinin octapeptide (CCK-8) in conscious rats.
(2) The stages of mourning involve cognitive learning of the reality of the loss; behaviours associated with mourning, such as searching, embody unlearning by extinction; finally, physiological concomitants of grief may influence unlearning by direct effects on neurotransmitters or neurohormones, such as cortisol, ACTH, or norepinephrine.
(3) Results suggest that Cd-MT is reabsorbed and broken down by kidney tubule cells in a physiological manner with possible subsequent release of the toxic cadmium ion.
(4) Nucleotide, which is essential for catalysis, greatly enhances the binding of IpOHA by the reductoisomerase, with NADPH (normally present during the enzyme's rearrangement step, i.e., conversion of a beta-keto acid into an alpha-keto acid, in either the forward or reverse physiological reactions) being more effective than NADP.
(5) This suggests that a physiological mechanism exists which can increase the barrier pressure to gastrooesophageal reflux during periods of active secretion of the stomach, as occurs in digestion.
(6) The effects of H1 and H2 antihistamines on a variety of physiological vasodilator responses were examined.
(7) A good understanding of upper gastrointestinal physiology is required to properly understand the pathophysiological events in various diseases or after operations on the upper gastrointestinal tract.
(8) This pattern was not seen for other physiologically active amino acids.
(9) These results suggest that aluminum is able to gain access to the central nervous system under normal physiological conditions.
(10) The physiological importance of this inhibition is discussed.
(11) The morphology and physiology of the large adapting unit (LAU: Fig.
(12) The use of 100% oxygen to calculate intrapulmonary shunting in patients on PEEP is misleading in both physiological and methodological terms.
(13) Considerable glucose 6-phosphatase activity survived 240min of treatment with phospholipase C at 5 degrees C, but in the absence of substrate or at physiological glucose 6-phosphate concentrations the delipidated enzyme was completely inactivated within 10min at 37 degrees C. However, 80mM-glucose 6-phosphate stabilized it and phospholipid dispersions substantially restored thermal stability.
(14) These results are consistent with a possible physiological role for medullary TRH in the vagal regulation of gastric contractility.
(15) The cells were taken from cultures in low-density balanced exponential growth, and the experiments were performed quickly so that the bacteria were in a uniform physiological state at the time of measurement.
(16) Atrioventricular (AV) delay that results in maximum ventricular filling and physiological mechanisms that govern dependence of filling on timing of atrial systole were studied by combining computer experiments with experiments in the anesthetized dog instrumented to measure phasic mitral flow.
(17) At physiologic doses (10(-8) M) estradiol inhibits the binding at a significant extent on the soluble receptor, but not on membrane-bound form.
(18) With the successful culture of these tissues, their development, biochemistry, and physiology, potentially of great importance in understanding early vertebrate evolution, can be better understood.
(19) The binding follows the principle of isotope dilution in the physiologic range of vitamin B12 present in human serum.
(20) Axonal regeneration with the ANG was equal to SAGs as measured by axonal diameters, physiological, and functional methods, although the SAG demonstrated statistically higher axonal counts.