Antagonism description

Cheng-Prasoff relationship, 65-66, 214 Cholecystokinin receptor antagonists, 80 Cimetidine, 9-10 Clark, Alfred J., 3, 3f, 12, 41 Clark plot, 114 Clearance, 165—166 Clinical pharmacokinetics, 165 Cocaine, 149, 150f Competitive antagonism description of, 114 Gaddum equation for, 101-102, 113,... 

Competitive antagonists affinity of, 261-264 description of, 75 IC50 correction factors for, 223 Schild analysis, 261-264 Concentration-dependent antagonism, 99 Concentration-response curve, 13 Confidence intervals, 228-229 Conformations, 13-14 Constitutive activity of receptors description of, 49—51 receptor density and, 56 Schild analysis, 108-111 Context-dependent biological effect, 188 Correction factors, 211-213, 223 Correlational research, 231 CP320626, 128... 

One-way analysis of variance, 229-230, 230f—231f Operational model derivation of, 54-55 description of, 45—47, 46f function for variable slope, 55 for inverse agonists, 221 of agonism, 47f orthosteric antagonism, 222 partial agonists with, 124, 220-221 Opium, 147 Orphan receptors, 180 Orthosteric antagonism... 

In the following, several terms used to describe interactions between chemicals are mentioned as well as basic concepts used in the hazard and risk assessment of chemical mixmres. The description of these basic concepts, first outlined by Bliss (1939) and Placket and Hewlett (1952), are based on the publications by Konemann and Pieters (1996), Cassee et al. (1998), and Groten et al. (2001). The definitions of additivity, synergism, antagonism, and potentiation are those of Klaassen (1995) and Seed et al. (1995). 

Although testing of the whole mixture as such seems to be the proper way to approach the risk assessment of exposure to that mixture, it will not provide data on combined actions and/or interactions between the individual components of the mixture. Even if the effect of the mixture is compared with the effects of each individual component at comparable concentrations, this will not allow a description of potential synergism, potentiation, or antagonism, and it is even doubtful that deviations from additivity can be concluded. This can only be achieved if dose-response curves are obtained for each of the single compounds. 

Explicit studies of opiate-receptors interactions should be very useful in continuing to explore the factors that modulate the extent of agonism and antagonism in a given opiate and the variation in this ratio among closely related analogues. Such studies are severely hampered on the experimental side by the lack of a detailed description of the opiate binding site. 

Although now there are numerous articles citing hormesis in various scientific databases, there are numerous other terms that have been used to describe dose-response relationships with the same quantitative features of the hormetic dose response. These similar descriptive terms include Yerkes-Dodson Law, nonmonotonic dose-response, nonlinear dose response, J-shaped dose-response, U-shaped dose-response, biphasic dose-response, BELL- haped dose-response, functional antagonism, hormologosis, overcompensation, rebound effect, bitonic, dual effect, bidirectional effect, bimodal effects, Amdt- chulz Law, Hueppe s Rule, and subsidy... 

Like in molecular quantum chemistry, the localized-delocalized antagonism is omnipresent in the theoretical literature on itinerant magnetism. On the one hand, the Hubbard model [292] and related theories for strongly correlated systems have been employed to study rare-earth and also transition metals. Since the latter do not have flat bands, extensions to the Hubbard theory are required [293-295] also, to make the model Hamiltonians (almost) exactly solvable, simplifications are introduced. On the other hand, density-functional theory is able to extract Stoner s parameters [296,297] for a self-consistent description of itinerant magnetism [298]. As has been illustrated before, the theoretical limits of the LDA became apparent from Fe phase stability problems (see Section 2.12.1) and were solved by using gradient corrections. The present status of DFT in the treatment of cooperative magnetism has also been reviewed [299]. 

The description of scientific thought as a pendulum movement between two opposite principles is not far from Meyerson s view as framed in Identity et rialiti (1908). Bachelard s emphasis on the pressing need for unity is not for from Meyerson s tendency for identification which is antagonized by the variety and plurahty opposed by reality. However, Bachelard never acknowledged any debt to Meyerson, who he contradicted on many points. In particular, he criticized Meyereon s interpretation of relativity theory in La valeur inductive de la relativite (1929), his response to Meyerson s La deduction relativiste (1925). 

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