Tissue Specific Sensitivity of Mitochondrial Permeability Transition Pore to Ca2+ Ions

René Endlicher,Pavla Křiváková,Halka Lotková,Marie Milerová,Zuzana Červinková,Zdeněk Drahota

doi:10.14712/18059694.2016.107

Abstract

Ca(2+)-induced opening of the mitochondrial permeability transition pore (MPTP) is involved in induction of apoptotic and necrotic processes. We studied sensitivity of MPTP to calcium using the model of Ca(2+)-induced, cyclosporine A-sensitive mitochondrial swelling. Presented data indicate that the extent of mitochondrial swelling (dA520/4 min) induced by addition of 25 microM Ca2+ is seven-fold higher in liver than in heart mitochondria (0.564 +/- 0.08/0.077 +/- 0.01). The extent of swelling induced by 100 microM Ca2+ was in liver tree times higher than in heart mitochondria (0.508 +/- 0.05/ 0.173 +/- 0.02). Cyclosporine A sensitivity showed that opening of the MPTP is involved. We may thus conclude that especially at low Ca2+ concentration heart mitochondria are more resistant to damaging effect of Ca2+ than liver mitochondria. These finding thus support hypothesis that there exist tissue specific strategies of cell protection against induction of the apoptotic and necrotic processes.

Highlights

Recent data in the literature have shown that mitochondria play an important role in induction of apoptotic and necrotic processes [9] and that mitochondrial membrane permeability transition pore (MPTP) is involved in cell death processes [3, 10]
In our work we focused on problems concerning tissue specific regulation of MPTP function because it has been shown that there exists physiological diversity of mitochondrial processes in various tissues [1]
We present complementary additional data showing that heart mitochondria are more resistant to calciuminduced opening of membrane permeability transition pore when compared with liver mitochondria

Summary

Introduction

Recent data in the literature have shown that mitochondria play an important role in induction of apoptotic and necrotic processes [9] and that mitochondrial membrane permeability transition pore (MPTP) is involved in cell death processes [3, 10]. Panov et al [16] observed specific differences in tolerance to calcium-induced swelling between liver and brain mitochondria. We present complementary additional data showing that heart mitochondria are more resistant to calciuminduced opening of membrane permeability transition pore when compared with liver mitochondria.

Results

Conclusion