Leptin Deficiency and Its Effects on Tibial and Vertebral Bone Mechanical Properties in Mature Genetically Lean and Obese JCR:LA-Corpulent Rats
Leptin signaling deficient rodents have emerged as models of obesity/insulin resistance syndrome. Altered leptin signaling, however, can affect axial and appendicular bone geometrical properties differently, and, thus, we hypothesized that leptin-deficiency would differentially influence mechanical...
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| Format: | Article |
| Language: | English |
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Wiley
2012-01-01
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| Series: | Journal of Obesity |
| Online Access: | http://dx.doi.org/10.1155/2012/650193 |
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| author | Raylene A. Reimer Jeremy M. LaMothe Ronald F. Zernicke |
| author_facet | Raylene A. Reimer Jeremy M. LaMothe Ronald F. Zernicke |
| author_sort | Raylene A. Reimer |
| collection | DOAJ |
| description | Leptin signaling deficient rodents have emerged as models of obesity/insulin resistance syndrome. Altered leptin signaling, however, can affect axial and appendicular bone geometrical properties differently, and, thus, we hypothesized that leptin-deficiency would differentially influence mechanical properties of vertebrae and tibiae compared to lean rats. Mature (9 mo) leptin receptor deficient obese (cp/cp; n=8) and lean (+/?; n=7) male JCR:LA-corpulent rats were used to test that hypothesis. Tibiae and the sixth lumbar vertebrae (L6) were scanned with micro-CT and were broken in three point-bending (tibiae) or axial loading (L6). Supporting the hypothesis, vertebrae and tibiae were differentially affected by leptin signaling deficiency. Tibiae, but not vertebrae, were significantly shorter in obese rats and achieved a significantly greater load (>18%), displacement (>15%), and stress (>18%) at the proportional limit, relative to the lean rats. Conversely, L6 in obese rats had significantly reduced displacement (>25%) and strain (>32%) at proportional limit, relative to the lean rats. Those combined results suggest that the etiology and duration of obesity may be important determinants of bone mechanical properties, and axial and appendicular bones may be affected differently. |
| format | Article |
| id | doaj-art-9022db03085c40349e3e502e722a87c2 |
| institution | Kabale University |
| issn | 2090-0708 2090-0716 |
| language | English |
| publishDate | 2012-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Journal of Obesity |
| spelling | doaj-art-9022db03085c40349e3e502e722a87c22025-02-03T05:58:39ZengWileyJournal of Obesity2090-07082090-07162012-01-01201210.1155/2012/650193650193Leptin Deficiency and Its Effects on Tibial and Vertebral Bone Mechanical Properties in Mature Genetically Lean and Obese JCR:LA-Corpulent RatsRaylene A. Reimer0Jeremy M. LaMothe1Ronald F. Zernicke2Faculties of Kinesiology and Medicine, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, CanadaFaculties of Kinesiology and Medicine, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, CanadaFaculties of Kinesiology and Medicine, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, CanadaLeptin signaling deficient rodents have emerged as models of obesity/insulin resistance syndrome. Altered leptin signaling, however, can affect axial and appendicular bone geometrical properties differently, and, thus, we hypothesized that leptin-deficiency would differentially influence mechanical properties of vertebrae and tibiae compared to lean rats. Mature (9 mo) leptin receptor deficient obese (cp/cp; n=8) and lean (+/?; n=7) male JCR:LA-corpulent rats were used to test that hypothesis. Tibiae and the sixth lumbar vertebrae (L6) were scanned with micro-CT and were broken in three point-bending (tibiae) or axial loading (L6). Supporting the hypothesis, vertebrae and tibiae were differentially affected by leptin signaling deficiency. Tibiae, but not vertebrae, were significantly shorter in obese rats and achieved a significantly greater load (>18%), displacement (>15%), and stress (>18%) at the proportional limit, relative to the lean rats. Conversely, L6 in obese rats had significantly reduced displacement (>25%) and strain (>32%) at proportional limit, relative to the lean rats. Those combined results suggest that the etiology and duration of obesity may be important determinants of bone mechanical properties, and axial and appendicular bones may be affected differently.http://dx.doi.org/10.1155/2012/650193 |
| spellingShingle | Raylene A. Reimer Jeremy M. LaMothe Ronald F. Zernicke Leptin Deficiency and Its Effects on Tibial and Vertebral Bone Mechanical Properties in Mature Genetically Lean and Obese JCR:LA-Corpulent Rats Journal of Obesity |
| title | Leptin Deficiency and Its Effects on Tibial and Vertebral Bone Mechanical Properties in Mature Genetically Lean and Obese JCR:LA-Corpulent Rats |
| title_full | Leptin Deficiency and Its Effects on Tibial and Vertebral Bone Mechanical Properties in Mature Genetically Lean and Obese JCR:LA-Corpulent Rats |
| title_fullStr | Leptin Deficiency and Its Effects on Tibial and Vertebral Bone Mechanical Properties in Mature Genetically Lean and Obese JCR:LA-Corpulent Rats |
| title_full_unstemmed | Leptin Deficiency and Its Effects on Tibial and Vertebral Bone Mechanical Properties in Mature Genetically Lean and Obese JCR:LA-Corpulent Rats |
| title_short | Leptin Deficiency and Its Effects on Tibial and Vertebral Bone Mechanical Properties in Mature Genetically Lean and Obese JCR:LA-Corpulent Rats |
| title_sort | leptin deficiency and its effects on tibial and vertebral bone mechanical properties in mature genetically lean and obese jcr la corpulent rats |
| url | http://dx.doi.org/10.1155/2012/650193 |
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