title: Effects of voluntary exercise and genetic selection for high activity levels on HSP72 expression in house mice.
abstract: We studied expression of heat shock protein 72 (HSP72) in female mice from four replicate lines that had been selectively bred for high voluntary wheel running (S) and from four random-bred control lines (C). Mice from generation 23 were sampled after 6 days of wheel access, and those from generation 14 were sampled after 8 wk of access to wheels either free to rotate or locked. Mice from S lines ran approximately 2.6 times as many revolutions per day as did those from C lines. Western blotting of tissues from generation 23 mice indicated that S mice had elevated HSP72 expression in triceps surae muscle, but levels in spleen, kidney, heart, and lung were similar in S and C mice. HSP72 expression in triceps surae from generation 14 mice was measured by ELISA and analyzed with a two-way analysis of covariance. The interaction between wheel type and line type (S vs. C) was statistically significant, and subsequent analyses indicated that S mice had significantly elevated HSP72 expression only when housed with free wheels. Mice with the previously described mini-muscle phenotype (Houle-Leroy P, Guderley H, Swallow JG, and Garland T Jr. Am J Physiol Regul Integr Comp Physiol 284: R433-R443, 2003) occurred in both generations and had elevated HSP72 expression in triceps surae. For the generation 23 sample, wheel running as a covariate had a significant negative association with HSP72 expression, and the effect of line type was still statistically significant. Therefore, the increased HSP72 expression of S mice is not a simple proximate effect of their increased wheel running.
authors.affiliation: Department of Zoology, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: Jason G
authors.initials: JG
authors.lastname: Belter
authors.forename: Hannah V
authors.initials: HV
authors.lastname: Carey
authors.forename: Theodore
authors.initials: T
authors.lastname: Garland
mesh_terms: D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006614:Hindlimb; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000502:physiology*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000378:metabolism*; D009929:Organ Size; D010641:Phenotype; D010807:Physical Endurance; D012641:Selection, Genetic; D013997:Time Factors
chemical_list: D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins