Inclusions in aged mitochondria.

The formation of paracrystalline inclusions in mitochondria following postmortem aging in situ is further investigated. Inclusions are found to localize either in the mitochondrial intracristal space or between the inner and outer membrane. The greater majority of the inclusions are of the intracristal type. pH is not an important factor in the formation of the inclusions, since lowering the pH of the mitochondrial suspensions does not increase the number of mitochondria with inclusions. It is concluded that changes associated with aging during the prolonged preservation of the mitochondria both in situ and in in vitro experiments are probably the principal cause for the formation of the mitochondrial inclusions.