What is the Origin of Mitochondrial Permeability Transition Pore?

The descriptive term combines the cellular location, "mitochondrial," with the functional outcome, "permeability transition," and the structural element, "pore." The recognition of this specific channel as a key regulator of cell death emerged from intensive research into mitochondrial bioenergetics in the late 20th century.

What is the Mechanism of Mitochondrial Permeability Transition Pore?

Pathological stimuli, such as high intracellular calcium concentrations or severe oxidative stress, induce a conformational change in the pore's components, causing it to open. This opening dissipates the crucial mitochondrial membrane potential, halting ATP synthesis and causing osmotic swelling of the organelle. The subsequent rupture of the outer membrane releases pro-apoptotic factors into the cytosol, committing the cell to programmed death.

Mitochondrial Permeability Transition Pore ∞ Area

Mitochondrial Permeability Transition Pore

Meaning

A non-selective, high-conductance channel formed transiently in the inner mitochondrial membrane, whose opening is a critical event in cellular injury and the initiation of both apoptosis and necrosis. The formation of the Mitochondrial Permeability Transition Pore (MPTP) is regulated by key cellular signals, including calcium overload, inorganic phosphate, and the redox state of the cell. Its irreversible opening leads to catastrophic mitochondrial failure and is a central feature in many chronic diseases.