Stochastic properties of competitive models for single ion channels in biological membranes

• Main Author: Elsheikh, E. K.
• Published: Swansea University 1982
• Subjects: 572
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636794

The object of this thesis is to provide some means of investigating the effect of a competitive blocking drug on the flow of current through ion-channels of muscle membrane, caused by the action of an agonist drug. It is also hoped that some of the quantities obtained may aid in assessing the plausibility of some mechanisms of drug action currently under consideration. Explicit expressions are derived for the various characteristics that govern the behaviour of single ion-channels in some competitive models of drug action. These include the distribution and corresponding means for some variables relating to bursts, apparent bursts and gaps within bursts and apparent bursts. Characteristics of some observable random variables, such as the mean length of the gap within the apparent burst, are plotted against the concentration of the agonist drug for different values of the concentration of the competitive drug. This is useful in relating theory to practice. A complete approximate solution for relaxation and fluctuations of membrane current is obtained for two finite (i.e. not assuming constant drug concentrations) competitive models. The method of solution can easily be generalized to other models, although computation may be necessary. Finally, an idea is provided on when it is reasonable to apply the easier solution for relaxation and fluctuations assuming constant drug concentrations.