title: Decay of mitochondrial metabolic competence in the aging cerebellum.
abstract: Cytochemically evidenced cytochrome oxidase activity was morphometrically measured in the cerebellar cortex of adult and old rats. The ratio (R) between the area of the precipitate due to the cytochemical reaction and the overall area of each mitochondrion was calculated. While in adult rats an inverse correlation between mitochondrial size and R values (r = -.905) was envisaged, in old animals increasing values of R were paired by increases in mitochondrial area (r =.561). Paired-quartile comparisons of the R values from adult and old animals documented a marked age-related impairment of the mitochondrial metabolic competence in small (I quartile: -31.6%) and medium-sized (II quartile: -26.4; III quartile: -16.4) mitochondria, while large organelles showed the lowest age-related decrease (IV quartile: -3.0%). The present findings support that a marked dysfunction of small and medium-sized mitochondria contributes to the significant decay of energy metabolism currently reported in physiological aging.
authors.affiliation: Neurobiology of Aging Laboratory, INRCA Research Department, 60121 Ancona, Italy. c.bertoni@inrca.it
authors.forename: Carlo
authors.initials: C
authors.lastname: Bertoni-Freddari
authors.forename: Patrizia
authors.initials: P
authors.lastname: Fattoretti
authors.forename: Belinda
authors.initials: B
authors.lastname: Giorgetti
authors.forename: Moreno
authors.initials: M
authors.lastname: Solazzi
authors.forename: Marta
authors.initials: M
authors.lastname: Balietti
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Di Stefano
authors.forename: Tiziana
authors.initials: T
authors.lastname: Casoli
mesh_terms: D000375:Aging; D000818:Animals; D002490:Central Nervous System / Q000473:pathology; D002531:Cerebellum / Q000473:pathology*; D003576:Electron Transport Complex IV / Q000378:metabolism; D008854:Microscopy, Electron; D008928:Mitochondria / Q000378:metabolism / Q000473:pathology*; D051381:Rats
chemical_list: D003576:Electron Transport Complex IV