Figure 1.

Mitochondrial swelling induced by CaCl₂. (A) Typical experiment showing the scattered light absorbance traces of Ca²⁺-induced swelling in response to addition of CaCl₂ to heart mitochondria isolated from rats transduced with shRNA-SCR (SCR, scrambled, control) in the presence or absence of cariporide (HOE642, 10 μ M) and Cyclosporine A (CsA, 10 mM). Cariporide and Cyclosporine attenuated Ca²⁺-induced mitochondrial swelling and the decrease in light scattering in mitochondrial suspensions. Cariporide inhibited the decrease in light scattering in a similar magnitude to CsA. (B) Scheme of a mitochondrion showing the CaCl₂-induced swelling in mitochondria that expresses scrambled sequence and functional NHE1, and possible mitochondrial site of action of the cariporide. This inhibitor could act on different mitochondrial mechanisms, including NHE. They could act through a decrease in mitochondrial Ca²⁺, H⁺, and ΔΨ m affecting the MPTP formation or altering the sensitivity to those factors to induce MPTP formation. Modified from Villa-Abrille et al. (2011).