How does mitochondrial Ca2+ change during ischemia and reperfusion? Implications for activation of the permeability transition pore.

Cardiac ischemia followed by reperfusion results in cardiac cell death, which has been attributed to an increase of mitochondrial Ca2+ concentration, resulting in activation of the mitochondrial permeability transition pore (PTP). Evaluating this hypothesis requires understanding of the mechanisms responsible for control of mitochondrial Ca2+ in physiological conditions and how they are altered during both ischemia and reperfusion. Ca2+ influx is thought to occur through the mitochondrial Ca2+ uniporter (MCU).

Restoring Atrial T-Tubules Augments Systolic Ca Upon Recovery From Heart Failure.

Background: Transverse (t)-tubules drive the rapid and synchronous Ca rise in cardiac myocytes. The virtual complete atrial t-tubule loss in heart failure (HF) decreases Ca release. It is unknown if or how atrial t-tubules can be restored and how this affects systolic Ca.