| Abstract: | The Modified Simplex Method (MSM) coupled with contour diagrams is used to determine the rate constants of a kinetic scheme involving three sequential second order processes. Reaction between glutathione and the dithiocarbamate fungicide tetramethylthiuram disulfide produces the oxidized form of glutathione which is then reduced in the presence of NADPH. The concentration of the reducing agent is monitored as a function of time. In the absence of simplifying assumption a closed form solution of the rate equations does not exist. Computed curves of NADPH concentration versus time were generated using the software SIMULCIN. The rate constant values are optimized by the MSM procedure to obtain the best agreement between calculated and experimental data. The significance, validity limits of the estimated rate constants and the relevance of these in vitro data to previous in vivo studies are discussed. |
