title: The effects of ad libitum feeding and marked dietary restriction on spontaneous skeletal muscle pathology in Sprague-Dawley rats.
abstract: The effects of ad libitum (AL) feeding and marked dietary restriction (DR) on spontaneous age-related skeletal muscle changes in male Sprague-Dawley (SD) rats were evaluated at 1 and 2 years. SD rats were fed Certified UAR A04C Rodent Chow ad libitum (AL), or DR at 50% of AL for (106 weeks). Body weights and organ weights were measured at the 1-year interim and 2-year final necropsies. In addition to the routine histopathologic examination, determination of 5 stereologic parameters was done in the vastus lateralis muscle after histochemistry of ATPase activity at 1 and 2 years. Body and skeletal muscle weights were proportional to the food intake. In AL-fed rats, muscle weights decreased between 1 and 2 years, in correlation with decreased type 2 myofiber numbers. In this group, fibrovascular index markedly increased with aging and muscle degeneration occurred at 2 years. In DR rats, there were no significant changes in muscle weights between 1 and 2 years. No histopathological changes were observed and the fibrovascular index was unchanged. These results demonstrated a protective effect of DR on the age-related skeletal muscle pathology in SD rats.
authors.affiliation: Merck Sharp & Dohme-Chibret Laboratories, Research Center, Department of Safety Assessment, Clermont-Ferrand Cedex 9, France. sylvain_molonnoblot@merck.com
authors.forename: Sylvain
authors.initials: S
authors.lastname: Molon-Noblot
authors.forename: Marie-Françoise
authors.initials: MF
authors.lastname: Hubert
authors.forename: Chao-Min
authors.initials: CM
authors.lastname: Hoe
authors.forename: Kevin
authors.initials: K
authors.lastname: Keenan
authors.forename: Philippe
authors.initials: P
authors.lastname: Laroque
mesh_terms: D000375:Aging / Q000473:pathology*; D000818:Animals; D001835:Body Weight; D005260:Female; D005508:Food Deprivation; D008297:Male; D018656:Muscle Fibers, Fast-Twitch / Q000473:pathology; D018482:Muscle, Skeletal / Q000473:pathology*; D009929:Organ Size; D044343:Overnutrition / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors