Evaluation of long-term vitamin E insufficiency or excess on bone mass, density, and microarchitecture in rodents.
High dietary α-tocopherol levels reportedly result in osteopenia in growing rats, whereas α-tocopherol deficiency in α-tocopherol transfer protein-knockout (α-TTP-KO) mice results in increased cancellous bone mass. Because osteoporosis is a disease associated primarily with aging, we hypothesized that age-related bone loss would be attenuated in α-TTP-KO mice. Cancellous and cortical bone mass and microarchitecture were assessed using dual-energy X-ray absorptiometry and micro-computed tomography in 2-year-old α-TTP-KO and wild-type (WT) male and female mice fed dl-α-tocopherol acetate. In contrast to our expectations, differences in cancellous bone were not detected between WT and α-TTP-KO mice of either gender, and α-TTP-KO males had lower (p<0.05) cortical bone mass than WT males. We therefore evaluated bone mass, density, and microarchitecture in proximal femur of skeletally mature (8.5-month-old) male Sprague-Dawley rats fed diets containing low (15 IU/kg diet), adequate (75 IU/kg diet), or high (500 IU/kg diet) dl-α-tocopherol acetate for 13 weeks. Low dietary α-tocopherol did not increase bone mass. Furthermore, no reductions in cancellous or cortical bone mass were detected with high dietary α-tocopherol. Failure to detect increased bone mass in aged α-TTP-KO mice or bone changes in skeletally mature rats fed either low or high levels of α-tocopherol does not support the hypothesis that α-tocopherol has a negative impact on bone mass, density, or microarchitecture in rodents.
Skeletal Biology Laboratory, Oregon State University, Corvallis, OR 97331, USA; Center for Healthy Aging Research, Oregon State University, Corvallis, OR 97331, USA.
Urszula T
UT
Iwaniec
Skeletal Biology Laboratory, Oregon State University, Corvallis, OR 97331, USA; Center for Healthy Aging Research, Oregon State University, Corvallis, OR 97331, USA.
Russell T
RT
Turner
Department of Nutritional Sciences, College of Human Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
Brenda J
BJ
Smith
Department of Nutritional Sciences, College of Human Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
Barbara J
BJ
Stoecker
Skeletal Biology Laboratory, Oregon State University, Corvallis, OR 97331, USA.
Allison
A
Rust
Biostatistics Core, School of Biological and Population Health Sciences, Oregon State University, Corvallis, OR 97331, USA.
Bo
B
Zhang
Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California at Davis, Davis, CA 95616, USA.
Vihas T
VT
Vasu
Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California at Davis, Davis, CA 95616, USA.
Kishorchandra
K
Gohil
Department of Internal Medicine, Genome and Biomedical Sciences Facility, University of California at Davis, Davis, CA 95616, USA.
Carroll E
CE
Cross
Linus Pauling Institute, Oregon State University, Corvallis, OR 97331, USA. Electronic address: maret.traber@oregonstate.edu.
Maret G
MG
Traber
D015502:Absorptiometry, Photon; D000375:Aging; D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D002352:Carrier Proteins / Q000235:genetics*; D004032:Diet; D005260:Female; D005269:Femur / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010024:Osteoporosis / Q000188:drug therapy / Q000235:genetics*; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species; D014811:Vitamin E Deficiency / Q000097:blood*; D055114:X-Ray Microtomography; D024502:alpha-Tocopherol / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
D002352:Carrier Proteins; D017382:Reactive Oxygen Species; C017763:alpha-tocopherol transfer protein; D024502:alpha-Tocopherol
Free radicals; Osteoporosis; Oxidative stress; Rodent; Skeleton; Vitamin E