Mitochondrial permeability transition (MPT) opens the Permeability Transition Pore Complex (PTPC)

Immediate loss of membrane potential cause swelling and rupture. Activated by Ca2+ accumulation and ROS at the inner membrane (IM). Or activated by BAK/BAX. PTPC sensitised by inhibition of BCL-2 antiapoptotic proteins by BH3 family (BID/BAD). BAK/BAX and BH3s can link the 2 MMP mechanisms.