• Open Access

Is defective electron transport at the hub of aging?


Drs Elena Maklashina and Brian A. C. Ackrell, Molecular Biology Division (151S), VA Medical Center, 4150 Clement Street, CA 94121, USA. Tel.: +1 415 752 9676; fax: +1 415 750 6959; e-mail: addresses: mclash@itsa.ucsf.edu, baca@pacbell.net


The bulwark of the mitochondrial theory of aging is that a defective respiratory chain initiates the death cascade. The increased production of superoxide is suggested to result in progressive oxidant damage to cellular components and particularly to mtDNA that encodes subunits assembled in respiratory complexes. Earlier studies of respiration in muscle mitochondria obtained from large cohorts of patients supported this notion by showing that either singly or in combinations, the respiratory complexes exhibited decreased activity in the elderly. The following critique of the most cited publications over the past decade points out the systematic errors that put earlier work at odds with recent findings. These later investigations indicate that aging has no overt effect on either the electron transport system or oxidative phosphorylation.