title: Effects of moderate calorie restriction on testosterone production and semen characteristics in young rhesus macaques (Macaca mulatta).
abstract: We have previously reported a modest influence of moderate calorie restriction (CR) on testicular gene expression in young adult rhesus macaques (Macaca mulatta); however, it is unclear if these modifications correspond to subsequent changes in testicular function or sperm physiology. This study extends our earlier findings to examine potential physiological differences due to this differential gene expression. Animals were subjected to 30% CR (CR, n = 5) or were fed a standard control diet (CON, n = 5) starting during their peripubertal period. Circulating testosterone (T) levels were measured across a 24-h period after 7 yr of dietary treatment and were found to be similar in CR and CON males; however, maintenance of daily minimum T levels was significantly higher in the CR animals. Semen collection was performed on the same cohort of animals three times per male (CR, n = 4; CON, n = 4) after 8 yr of treatment, and samples were assessed by a variety of measures. Parameters, including semen quality and sperm cell viability and function, showed less variability in semen samples taken from CR males, but overall testicular function and sperm quality were comparable regardless of diet. There is mounting evidence that CR may promote health and longevity in a wide range of organisms, including nonhuman primates. Importantly, our data suggest that moderate CR has no obvious lasting detrimental effect on testicular function and sperm parameters in young adult primates and may in fact help maintain higher levels of circulating T.
authors.affiliation: Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland, USA
authors.forename: Brandon D
authors.initials: BD
authors.lastname: Sitzmann
authors.forename: Erin H
authors.initials: EH
authors.lastname: Leone
authors.forename: Julie A
authors.initials: JA
authors.lastname: Mattison
authors.forename: Donald K
authors.initials: DK
authors.lastname: Ingram
authors.forename: George S
authors.initials: GS
authors.lastname: Roth
authors.forename: Henryk F
authors.initials: HF
authors.lastname: Urbanski
authors.forename: Mary B
authors.initials: MB
authors.lastname: Zelinski
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Ottinger
mesh_terms: D000367:Age Factors; D000818:Animals; D031204:Caloric Restriction / Q000662:veterinary*; D015331:Cohort Studies; D005434:Flow Cytometry; D008137:Longitudinal Studies; D008253:Macaca mulatta / Q000097:blood / Q000378:metabolism / Q000502:physiology*; D008297:Male; D012621:Seasons; D012661:Semen / Q000378:metabolism*; D013076:Sperm Count / Q000662:veterinary; D013081:Sperm Motility / Q000502:physiology; D013737:Testis / Q000378:metabolism*; D013739:Testosterone / Q000096:biosynthesis* / Q000097:blood
chemical_list: D013739:Testosterone