[Simple bimolecular reaction model with physical feedback mechanism in the handling of rhythmic processes and their modification of receptor populations].
A bimolecular reaction model considering a physical feedback by the concentration dependence of a kinetic coefficient is proposed for the description of the receptor action. The regulatory properties will be treated in the framework of nonequilibrium thermodynamics as dynamic critical phenomena. The receptor and the bioactive agent are regarded as a system working in the vicinity of an instability point. The kinetics contains the possibility for a bifurcation to a limit cycle behavior, a stable time-periodic solution. For the transition regime, the relevant order parameter and its evolution equation can be determined with the help of a reductive pertubation approach. On this way, the magnitude of the receptor output signal may be obtained via its dependence on some essential parameters. The influence of environmentally produced fluctuations is incorporated by a Gaussian white-noise. For the stochastic model, the static probability distributions are calculated yielding some potential laws for the behavior of interesting state variables. The model results will be useful for the understanding of certain receptor related phenomena as for instance sigmoidal relationships between the response and the dose, tachyphylaxis and specific desensitization, temporal oscillations of some concentrations, and modulation effects caused by co-factors. Within the model, pertubations can be included such as a stochastic parameter variation or a competitive mechanism.
Seese
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Forschungsgruppe für Pharmakochemie, Karl-Marx-Universität Leipzig, Bereich Medizin.
Mager
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D000818:Animals; D002628:Chemoreceptor Cells / Q000502:physiology*; D005246:Feedback; D006801:Humans; D007700:Kinetics; D008433:Mathematics; D008958:Models, Molecular; D008959:Models, Neurological
Einfaches bimolekulares Reaktionsmodell mit physikalischem Feedback-Mechanismus zur Behandlung rhythmischer Prozesse und deren Beeinflussung an Receptor-Populationen.