Abstract
Study Design: Both forelimbs of rats were amputated and these rats were kept in the custom-made cages to keep prolonged and repeated upright posture. Changes of bone were observed in the lumbar vertebrae at three different time points after the surgery. Objective: To investigate the effect of prolonged and repeated upright posture on the cartilage end plate of rat lumbar vertebrae. Summary of Background Data: Previous studies show calcified hypertrophy is related to mechanical stress, but there are no clear evidences to indicate whether or not long-term and repeated assumption of the upright posture could result in calcified hypertrophy in cartilage end plate of rat lumbar spine. Methods: The forelimbs of 30 rats were amputated when they were 1 month old. These rats were kept in the custom-made cages and were forced to stand upright on their hind-limbs and tails to obtain water and food. Normal rats of the same ages kept in regular cages were used as control. The rats were killed at 5, 7, and 9 months after the surgery and lumbar vertebrae samples were harvested for micro-CT, histologic, and immunohistochemical studies. Total RNA isolated from these samples were used for real-time RT-PCR of type X collagen (Col10α1), vascular endothelial growth factor (VEGF), and transforming growth factor β1 (TGF-β1). Results: Micro-CT showed increased inner part of cartilage end plate. Histologic revealed peripheral hypertrophy of disc after the surgery. Immunostaining and real-time RT-PCR showed increased protein and mRNA expression of type X collagen, VEGF, and TGF-β1. Conclusion: Prolonged upright posture induces cartilage end plate calcification and hypertrophy in rat lumbar spine.
Original language | English (US) |
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Pages (from-to) | 2011-2020 |
Number of pages | 10 |
Journal | Spine |
Volume | 36 |
Issue number | 24 |
DOIs | |
State | Published - Nov 15 2011 |
Externally published | Yes |
Keywords
- calcification
- cartilage end plate
- hypertrophy
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Clinical Neurology