Characteristics of bone turnover, bone mass and bone strength in Spontaneously Diabetic Torii-Lepr fa rats.
The Spontaneously Diabetic Torii-Lepr (fa) (SDT-fa/fa) rat is a new model of obese type 2 diabetes. The SDT-fa/fa rat shows obesity and hyperglycemia at a young age compared to the Spontaneously Diabetic Torii (SDT-+/+) rat; however, bone abnormalities in the SDT-fa/fa rat have not been investigated. The objective of the present study was to investigate the effects of obese type 2 diabetes on bone turnover, bone mass, and bone strength in the SDT-fa/fa rat. Sprague-Dawley rats were used as control animals, and SDT-+/+ rats were used as non-obese type 2 diabetic rats. Serum osteocalcin and urine deoxypyridinoline levels were decreased in SDT-fa/fa rats compared to control rats at a young age. SDT-fa/fa rats showed decreases in bone mineral density and bone mineral content of the whole tibia, and shortening of the tibia and femur compared to control and SDT-+/+ rats. Deterioration in bone geometrical properties of the femur midshaft such as cortical thickness and minimum moment of inertia, was observed in SDT-fa/fa rats compared to control and SDT-+/+ rats. Furthermore, trabecular bone volume of the distal femur was decreased in SDT-fa/fa rats compared to control rats. These negative effects on bone in SDT-fa/fa rats caused severe decreases in maximum load, stiffness, and energy absorption of the femur. In addition, serum levels of homocysteine, a candidate for bone fragility markers, were elevated in SDT-fa/fa rats compared to control and SDT-+/+ rats. In conclusion, the SDT-fa/fa rat may be a useful model to investigate bone abnormalities in obese type 2 diabetes.
Biological/Pharmaceutical Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc., 1-1, Murasaki-cho, Takatsuki, Osaka, 569-1125, Japan. shuichi.kimura@jt.com
Shuichi
S
Kimura
Tomohiko
T
Sasase
Takeshi
T
Ohta
Eimei
E
Sato
Mutsuyoshi
M
Matsushita
D000596:Amino Acids / Q000652:urine; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D015519:Bone Density; D016723:Bone Remodeling / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000503:physiopathology* / Q000652:urine; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology* / Q000652:urine; D005269:Femur / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D006710:Homocysteine / Q000097:blood; D021621:Imaging, Three-Dimensional; D008297:Male; D009929:Organ Size; D015675:Osteocalcin / Q000097:blood; D011859:Radiography; D051381:Rats; D054411:Receptors, Leptin / Q000235:genetics*; D013977:Tibia / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology
D000596:Amino Acids; D001786:Blood Glucose; D054411:Receptors, Leptin; D006710:Homocysteine; D015675:Osteocalcin; C036020:deoxypyridinoline; D002118:Calcium