Tallarida R J, Freeman K A
Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140.
Ann Biomed Eng. 1994 Mar-Apr;22(2):153-61. doi: 10.1007/BF02390373.
Endogenous compounds, such as hormones and neurotransmitters, interact with cellular receptors in controlled reactions governed by the mass-action law. Autoreceptors, a subset of the receptor pool, when activated by the endogenous ligand, result in a negative feedback that reduces the further release of ligand. This paper discusses and illustrates this control system when the concentrations (free and bound) are near or slightly beyond the limits of effective feedback control. Specifically, a forced periodic input function, simulating periodic release of the ligand, is used in the simulation of this controlled binding reaction in which a parameter representing the upper limit of control is varied. The solution of the system differential equations, representing free and bound ligand, is shown to pass from periodic to chaotic as the parameter is varied.
内源性化合物，如激素和神经递质，在质量作用定律支配的受控反应中与细胞受体相互作用。自身受体是受体库的一个子集，当被内源性配体激活时，会产生负反馈，从而减少配体的进一步释放。本文讨论并阐述了当（游离和结合的）浓度接近或略超出有效反馈控制极限时的这种控制系统。具体而言，在该受控结合反应的模拟中，使用了一个模拟配体周期性释放的强制周期性输入函数，其中代表控制上限的一个参数是变化的。表示游离和结合配体的系统微分方程的解表明，随着该参数的变化，会从周期性转变为混沌状态。
