Until recently the kidney has not been considered as an important organ in iron metabolism. However, the investigation of last decade showed that even under physiological conditions significant amounts of iron proteins undergo glomerular filtration and are reabsorbed in the proximal tubule. In the case of hemolytic diseases exposition of the kidney towards iron is increased and dependent on plasma haptoglobin level. Uptake of iron protein in the proximal tubule occurs via endocytosis mediated by a tandem of receptors megalin and cubilin.

Apoptosis in adult organism plays a role in removing of unnecessary, damaged or potentially dangerous cells. Apoptosis inducing factors include DNA damaging factors, such as oxidative stress or partial ischemia. Physical exercise may lead to disturbance and damage in many organs, especially in untrained organisms. It has been demonstrated that an intense exercise could finally lead to apoptosis in skeletal muscles, however apoptotic changes were restricted to single myonuclei.