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. Author manuscript; available in PMC: 2011 Aug 15.

Published in final edited form as: Free Radic Biol Med. 2010 Jun 2;49(4):567–579. doi: 10.1016/j.freeradbiomed.2010.04.037

Fig. 6 — IsoKs accelerate the rate of the mPT induction but not the order of the reaction. A. Dependence of k₁ (the Ca²⁺ uptake rate) on the presence of IsoKs. B. Dependence of n (the reaction order) on the presence of IsoKs. C. Dependence of k₂′ (rate of the mPT induction) on the presence of IsoKs. The kinetic analysis was performed using a recently introduced kinetic model (54). The model functionally resolves possible sites of action for different mPT modulators.

where [MH-(Ca²⁺)_i]_A represents the population of active, unswollen mitochondria ([MH]_A), i being the number of Ca²⁺ already adsorbed by a given mitochondria. Ca²⁺ uptake occurs during the k₁ step shown in scheme as formation of [MH-(Ca²⁺)_i+1]_A, and it initiates the mPT process that we describe as a sequence of two steps. The k₂ step is rate-limiting step of the mPT induction that results in the formation of the intermediate state [MH]_I and depends on the reaction constant k₂′. The next step (k_p) leads to the formation of a population of inactive (swollen) mitochondria, represented as [MH]_N, with all Ca²⁺ released back to the medium. [Ca²⁺]_out is the concentration of free Ca²⁺ in the medium, available for absorption by mitochondria. Data were plotted as the mean ± sem, N=3, *, p < 0.05 compare with IsoKs untreated mitochondria.

graphic file with name nihms206239e2.jpg — IsoKs accelerate the rate of the mPT induction but not the order of the reaction. A. Dependence of k₁ (the Ca²⁺ uptake rate) on the presence of IsoKs. B. Dependence of n (the reaction order) on the presence of IsoKs. C. Dependence of k₂′ (rate of the mPT induction) on the presence of IsoKs. The kinetic analysis was performed using a recently introduced kinetic model (54). The model functionally resolves possible sites of action for different mPT modulators.

where [MH-(Ca²⁺)_i]_A represents the population of active, unswollen mitochondria ([MH]_A), i being the number of Ca²⁺ already adsorbed by a given mitochondria. Ca²⁺ uptake occurs during the k₁ step shown in scheme as formation of [MH-(Ca²⁺)_i+1]_A, and it initiates the mPT process that we describe as a sequence of two steps. The k₂ step is rate-limiting step of the mPT induction that results in the formation of the intermediate state [MH]_I and depends on the reaction constant k₂′. The next step (k_p) leads to the formation of a population of inactive (swollen) mitochondria, represented as [MH]_N, with all Ca²⁺ released back to the medium. [Ca²⁺]_out is the concentration of free Ca²⁺ in the medium, available for absorption by mitochondria. Data were plotted as the mean ± sem, N=3, *, p < 0.05 compare with IsoKs untreated mitochondria.