Influence of Captopril Treatment of Plasma Renin Activity � Mathematical Model

Abstract

A model of the dynamics of plasma renin activity under the influence of various doses of captopril is formulated. The influence of captopril on renin angiotensin system is different from the effects of the other studied drugs nifedipine and nicardipine. Captopril inhibits the feedback in renin-angiotensin system and the upward trend of the renin activity is a proportional of the intrinsic growth rate. This dependence can be described using a modified Verhulst logistic function is proposed. The model is identified using the Korelia-Dynamics program. As optimization method for data identification a cyclic coordinate descent method is used. The residuals between the experimental data and the identified model are minimized applying least square or uniform fitting. The model allows prediction the effects of different captopril doses and permits the researcher to study the behavior of the renin angiotensin system under variety of conceivable conditions.