(v. t.) To contend with; to oppose actively; to counteract.
(v. i.) To act in opposition.
Example Sentences:
(1) Intrathecal injection of zopiclone potentiated morphine antinociception, while the intracerebroventricular injection of zopiclone failed to enhance morphine antinociception and the intracerebroventricular injection of flumazepil to antagonize the intraperitoneal-zopiclone-induced increase in morphine antinociception.
(2) of PLA2 caused marked degranulation of mast cells in the rat mesentery which was facilitated by addition of calcium ion (10 mM) but antagonized by pretreating with three antiinflammatory agents.
(3) [Ca2+]i exhibited a sigmoidal dependence on [Na+]o. Mg2+, a competitive inhibitor of Na2+-Ca2+ antiport in these cells, antagonized the increase in [Ca2+]i produced by lowering [Na+]o.
(4) Increases in extracellular calcium antagonized the negative inotropic effect.
(5) In K+-depolarized basilar arteries, ifenprodil competitively antagonized the response to Ca2+, and this was enhanced by pre-incubation in calcium hopantenate.
(6) During the postovulatory phase, endogenous progesterone and the production of metabolites antagonized this effect.
(7) An antagonism is unlikely when ciprofloxacin is combined with one of the beta-lactams studied or with tobramycin.
(8) Co-application of CGS 9896, a benzodiazepine receptor antagonist, did not antagonize the guanidino compound-induced inhibition of GABA responses.
(9) Aortic rings from the rabbit were similarly potently antagonized by the protein kinase C inhibitors, however, K(+)-induced contractions were also equally sensitive to these agents in both rat and rabbit tissues.
(10) The biphasic response to (-)-(S)-Bay K 8644 and (+)-(S)-202-791 suggests that the properties of Ca++ channel activation and antagonism may reside within a single 1,4-dihydropyridine molecule.
(11) We have investigated the bacterial antagonism exerted in oral secretion by alpha-hemolytic streptococci against S. aureus and S. epidermidis.
(12) The marine natural product lophotoxin has produced a non-reversible antagonism of parasympathetic and sympathetic functions that are known to be mediated by C6 sub-type nicotinic receptors.
(13) Strains showing occasional antagonism at a particular proportion of concentrations of the test combination, were found to only be indifferent when the mean index of the fractional inhibition concentration of all checkerboard combinations was calculated.
(14) The omission of glucose induced a marked increase in the efflux of [3H]GABA, which was antagonized by TTX (1 microM), but not by MK 801 (1 microM) or DNQX (100 microM).
(15) The hyperthermia in rabbits caused by the serotonergic stimulants cited above is also antagonized by pretreatment with MS.
(16) The neuroleptic agents haloperidol, fluphenazine, domperidone, sulpiride and tiapride also antagonized emesis induced by cisplatin but only a proportion of the animals were completely protected and diazepam and prednisolone only reduced the intensity of the response.
(17) These results suggest that formoterol modifies allergen-induced airway responses through functional antagonism rather than the inhibition of inflammatory cell infiltration.
(18) Depolarizations induced by acetyl-Arg6-septide, a NK1-receptor selective agonist, were also antagonized by spantide with a pA2 of 6.5.
(19) 5-Hydroxytryptamine contracted the musculature from all parts of the respiratory tract-an effect which was specifically antagonized by both methysergide and atropine.4.
(20) K showed little activity against LTC4 but could antagonize more selectively H- and ACh-mediated effects.
Counteract
Definition:
(v. t.) To act in opposition to; to hinder, defeat, or frustrate, by contrary agency or influence; as, to counteract the effect of medicines; to counteract good advice.
Example Sentences:
(1) The origins of aging of higher forms of life, particularly humans, is presented as the consequence of an evolved balance between 4 specific kinds of dysfunction-producing events and 4 kinds of evolved counteracting effects in long-lived forms.
(2) Conversely, rat galanin increased unstimulated glucagon output (approximately 20%, P less than 0.05), potentiated the glucagon response to arginine (approximately 50%, P less than 0.05) and VIP (approximately 90%, P less than 0.05), and counteracted the suppressor effect of glucose on alpha-cell secretion.
(3) This inhibition is counteracted by the somewhat slower increase of NE turnover resulting in normalization of LH levels.
(4) These results suggest that CPZ interacts with smg p21B, smg GDS, or both, and thereby inhibits the smg GDS action, and that CPZ also interacts with the acidic phospholipids and thereby counteracts their inhibitory effect on the smg GDS action.
(5) Extracts from arrested cells counteracted the stimulating effects of extracts from proliferating cells with kinetics suggesting competitive interaction between stimulating and inhibitory factors.
(6) Acetylcholine increases their turnover, Atropine reduces it, and the addition of atropine counteracts the effect of acetylcholine in all these phospholipids.
(7) Whether they affect ureteral motility in vivo or whether they can counteract ureteral spasm associated with ureteral stones have not been established.
(8) Metoclopramide did not counteract the apomorphine effect and, in higher doses, water intake was even further reduced.
(9) This effect increases with the estrogen dose and is counteracted more effectively by androgenic progestogens such as levonorgestrel than by nonandrogenic progestogens such as desogestrel.
(10) PGE2 counteracted the NA-effect in the former group of patients but did not affect the influence of NA at term.
(11) Addition of heme in vitro (10(-6)M) to the latter nuclei results in a significant counteraction of the decreased cytochrome P-450 (c + d) mRNA transcription.
(12) Two functions of these have been proposed: 1) that they are compatible osmolytes which regulate cell volume (against high external NaCl) without inhibiting proteins and 2) that methylamines (GPC and betaine) are counteracting osmolytes which stabilize proteins against perturbation from high renal urea.
(13) For this rather large pressures (about 700 hPa) are required to overcome the surface forces counteracting droplet formation.
(14) The drop in the blood-sugar levels was counteracted by corresponding infusions of glucose by the BIOSTATOR via a special clamp technique.
(15) In the wild strain (Em 5297a) thiourea is tenfold more toxic on an allantoin medium than on an inorganic nitrogen medium; allantoin as well as urea counteract thiourea toxicity in the allantoin nitrogen medium.
(16) Retinal traction can be counteracted by the oil up to a calculated threshold value, depending on the size and shape of the tear, the strength of the surface tension and, most importantly, the distance between the retina and choroid.
(17) Some of the changes found may be a result of adaptive mechanisms occurring in order to counteract the different biophysical effects of ethanol.
(18) This study evaluates whether suturing of replaced flaps with crown-attached sutures, following reconstructive surgery, counteracts postoperative recession of the gingival margins and facilitates new attachment.
(19) In the present article is shown that the histamine releasing effect is counteracted by the addition of histamine to the superfusion fluid.
(20) This barrier effect was partially counteracted by monensin or carbonyl cyanide m-chlorophenylhydrazone.