title: Effects of methionine restriction and endurance exercise on bones of ovariectomized rats: a study of histomorphometry, densitometry, and biomechanical properties.
abstract: To investigate the effects of dietary methionine restriction (MetR) and endurance exercise on bone quality under a condition of estrogen deficiency, female Sprague-Dawley rats (36-wk-old) were assigned to a sham surgery group or one of five ovariectomized groups subjected to interventions of no treatment (Ovx), endurance exercise (Exe), methionine restriction (MetR), methionine restriction plus endurance exercise (MetR + Exe), and estrogen treatment (Est). Rats in the exercise groups were subjected to a treadmill running regimen. MetR and control diets contained 0.172 and 0.86% methionine, respectively. After the 12-wk intervention, all animals were killed, and serum and bone tissues were collected for analyses. Compared with estrogen treatment, MetR diet and endurance exercise showed better or equivalent efficiency in reducing body weight gain caused by ovariectomy (P < 0.05). Whereas only the Est group showed evidence for reduced bone turnover compared with the Ovx group, MetR diet and/or endurance exercise demonstrated efficiencies in downregulating serum insulin, leptin, triglyceride, and thiobarbituric acid reactive substances (P < 0.05). Both the Exe and MetR groups showed higher femoral cortical and total volumetric bone mineral density (vBMD), but only the Exe and Est groups preserved cancellous bone volume and/or vBMD of distal femora (P < 0.05) compared with the Ovx group. After being normalized to body mass, femora of the MetR and MetR + Exe groups had relatively higher bending strength and dimension values followed by the Sham, Exe, and Est groups (P < 0.05). In conclusion, both MetR diet and endurance exercise improved cortical bone properties, but only endurance exercise preserved cancellous bone under estrogen deficiency.
authors.affiliation: Institute of Physical Education, Health and Leisure Studies, National Cheng Kung University, Tainan, Taiwan; tsanghai@mail.ncku.edu.tw.
authors.forename: Tsang-Hai
authors.initials: TH
authors.lastname: Huang
authors.affiliation: Institute of Physical Education, Health and Leisure Studies, National Cheng Kung University, Tainan, Taiwan;
authors.forename: I-Hsiu
authors.initials: IH
authors.lastname: Su
authors.affiliation: Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, Minnesota;
authors.forename: Jack L
authors.initials: JL
authors.lastname: Lewis
authors.affiliation: Department of Biochemistry and Molecular Biology, National Cheng Kung University, Tainan, Taiwan;
authors.forename: Ming-Shi
authors.initials: MS
authors.lastname: Chang
authors.affiliation: Department of Physical Therapy, National Cheng Kung University, Tainan, Taiwan; and.
authors.forename: Ar-Tyan
authors.initials: AT
authors.lastname: Hsu
authors.affiliation: Orentreich Foundation for the Advancement of Science, Cold Spring-on-Hudson, New York.
authors.forename: Carmen E
authors.initials: CE
authors.lastname: Perrone
authors.affiliation: Orentreich Foundation for the Advancement of Science, Cold Spring-on-Hudson, New York.
authors.forename: Gene P
authors.initials: GP
authors.lastname: Ables
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects / Q000502:physiology; D015519:Bone Density / Q000187:drug effects / Q000502:physiology; D001842:Bone and Bones / Q000187:drug effects* / Q000503:physiopathology*; D003720:Densitometry / Q000379:methods; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D008715:Methionine / Q000378:metabolism*; D010052:Ovariectomy / Q000379:methods; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004967:Estrogens; D008715:Methionine
keywords: amino acid; body weight; dietary restriction; estrogen deficiency