Search results for "antagonism"

Ascorbic acid antagonizes ethanol-induced locomotor activity in the open-field.

1999

Abstract It has been reported that ascorbic acid (AA) antagonizes the physiological and behavioral effects of dopamine (DA). AA reduces locomotor activity induced by dopaminergic agonist drugs. Also, AA amplifies the action of antidopaminergic drugs. Ethanol, like other drugs, produces a release of DA in the mesolimbic pathway, and at some doses, induces locomotor activity in mice. The ethanol-induced locomotor activity could be dopamine-dependent because it can be reduced by antidopaminergic drugs. In the present study, we investigated whether an acute administration of AA reduces ethanol-induced locomotor behavior. AA, at doses (0.0, 21.85, 87.5, 175, 350, and 1400 mg/kg) was injected IP …

Mechanism underlying the inhibitory sidebands in the receptive field of simple striate cells of the cat: pure on/off antagonism only or true inhibiti…

1985

The intrinsic organization of the receptive fields of simple striate cells revealed by moving stimuli is much more complex than could have been suspected from the use of stationary ones. There is, in fact, a small excitatory region centrally located in these receptive fields and an inhibitory region encompassing the whole excitatory component. These inhibitory regions or “inhibitory sidebands”, were identified by stimulating the cells with bars of light against anartificial background discharge produced by repeated asynchronous stimulation of the excitatory component of the cell's receptive field. For a long time' these inhibitory sidebands have been accounted for on the basis of the recept…

Toxicological interactions between the mycotoxins beauvericin, deoxynivalenol and T-2 toxin in CHO-K1 cells in vitro.

2011

Abstract Beauvericin (BEA), deoxynivalenol (DON) and T-2 toxin (T-2) are important food-borne mycotoxins that have been implicated in human health. In this study, the acute toxicity of individual and combined mycotoxins (BEA, DON and T-2) were tested in immortalized hamster ovarian cells (CHO-K1) at 24, 48 and 72 h of exposure, by the tetrazolium salt (MTT) and neutral red (NR) assays. The IC50 values obtained for all mycotoxins by the MTT and NR assays ranged from 0.017 to 12.08 μM and from 0.042 to 17.22 μM, respectively. Both, individual and combined mycotoxins demonstrated a significant cytotoxic effect in CHO-K1 cells in a dose-dependent manner. When mycotoxins were assayed individuall…

Molecular markers and biological targeted therapies in metastatic colorectal cancer: expert opinion and recommendations derived from the 11th ESMO/Wo…

2010

The article summarizes the expert discussion and recommendations on the use of molecular markers and of biological targeted therapies in metastatic colorectal cancer (mCRC), as well as a proposed treatment decision strategy for mCRC treatment. The meeting was conducted during the 11th ESMO/World Gastrointestinal Cancer Congress (WGICC) in Barcelona in June 2009. The manuscript describes the outcome of an expert discussion leading to an expert recommendation. The increasing knowledge on clinical and molecular markers and the availability of biological targeted therapies have major implications in the optimal management in mCRC. 21 Suppl 6 vi1 10

In "semi-vivo" antagonism of Acremonium byssoides towards Plasmopara viticola.

2008

Der Antagonismus verschiedener Sympatholytica gegen�ber dem inhibitorischen Adrenalin- oder Noradrenalineffekt am elektrisch gereizten Meerschweinche…

1958

Adrenaline and noradrenaline were found to depress the contractions of the electrically stimulated isolated ileum of the guinea-pig; this action was related to the dose. In these experiments smaller amounts of adrenaline were required than those necessary for the depression of the spontaneous movements of the isolated rabbit duodenum.

El último intelectual (y 4). Un modelo

2007

Pseudomonas corrugata contains a conserved N-acyl homoserine lactone quorum sensing system; its role in tomato pathogenicity and tobacco hypersensiti…

2007

Pseudomonas corrugata is a phytopathogenic bacterium, causal agent of tomato pith necrosis, yet it is an ubiquitous bacterium that is part of the microbial community in the soil and in the rhizosphere of different plant species. Although it is a very heterogeneous species, all the strains tested were able to produce short chain acyl homoserine lactone (AHL) quorum sensing signal molecules. The main AHL produced was N-hexanoyl-l-homoserine lactone (C6-AHL). An AHL quorum sensing system, designated PcoI/PcoR, was identified and characterized. The role of the quorum sensing system in the expression of a variety of traits was evaluated. Inactivation of pcoI abolished the production of AHLs. The…

The effects of the tricyclic antidepressants desipramine, doxepin and iprindole on the isolated perfused rabbit heart.

1974

1. The right sympathetic nerves of isolated perfused rabbit hearts were stimulated electrically (1 msec, supramaximal strength, 15 sec) with increasing frequencies (0.25–20 Hz) at 3 min intervals before and 20 min after starting perfusion with desipramine, doxepin or iprindole. Ventricular rate, right atrial and right ventricular tensions were recorded using the transverse method. 2. Sympathic nerve stimulation caused ventricular arrhythmias in the presence of desipramine (3.3 and 5.0 · 10−6 M) and doxepin (1.6−4.7×10−6 M) but failed to produce arrhythmias in hearts not exposed to drugs, or after iprindole, cocaine and atropine. 3. When desipramine or doxepin was added to Tyrode solution co…

In semi-vivo antagonism of Acremoninum byssoides towards Plasmopara viticola

2008

In previous laboratory tests the culture filtrates and the crude extracts obtained from Acremonium byssoides were shown to completely inhibit Plasmopara viticola sporangia germination. A study was thus undertaken in order to investigate on the possible inhibiting activity of the hyphomycete towards pathogenesis of the oomycete in grapevine. A. byssoides was cultivated on malt-extract agar (MEA) to obtain pure colonies and on maltextract broth (MEB) to obtain culture filtrate and crude extract. Healthy leaves of grapevine were put in Petri dishes containing sporangia suspended in: deionized sterile water, malt-extract broth, dimethylsulfoxide (DMSO), culture filtrate, crude extract and a sus…