Changes in Bone Metabolism in Young Castrated Male Rats.
OBJECTIVE
To determine the window of time during which osteoporosis affects the management of spinal surgery and the mechanism of bone metabolism changes in males with osteoporosis by examining changes in bone metabolism in young castrated male rats.


METHODS
A total of 30 Sprague-Dawley rats were randomly allocated into two study groups. Group 1 (control) received a sham surgery and Group 2 received bilateral orchiectomy to change bone mineral density (BMD). Serum osteocalcin, alkaline phosphatase (ALP), and collagen type 1 cross-linked C-telopeptide (CTX) were analyzed at postoperative date (POD) 8, 10, and 12 weeks. BMDs were measured using micro computed tomography scans.


RESULTS
Femoral and lumbar BMDs were decreased in the orchiectomy groups. BMDs in the sham and orchiectomy groups showed statistically differences at POD 8, 10, and 12 weeks for the femur (p=0.032, 0.008, 0.008) and lumbar spine (p=0.151, 0.008, 0.008, respectively). Serum osteocalcin, ALP, and CTX decreased gradually; however, N-terminal type 1 procollagen (P1NP) showed a slight increase yet no significant change.


CONCLUSIONS
In young castrated male rats, a significant decrease in BMD was observed after orchiectomy due to the mixture of two detrimental factors. Young castrated male rats did not reach peak BMD. Increased bone turnover causes bone resorption to exceed bone formation. This study may contribute to the creation of a valuable model for studies of male osteoporosis and the spinal surgery field.
Department of Neurosurgery, The Spine and Spinal Cord Institute, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Seong Jun
SJ
Ryu
Department of Neurosurgery, The Spine and Spinal Cord Institute, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Dal Sung
DS
Ryu
Department of Neurosurgery, The Spine and Spinal Cord Institute, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Jong Yeol
JY
Kim
Department of Neurosurgery, The Spine and Spinal Cord Institute, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Jeong Yoon
JY
Park
Department of Neurosurgery, The Spine and Spinal Cord Institute, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Kyung Hyun
KH
Kim
Department of Neurosurgery, The Spine and Spinal Cord Institute, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Dong Kyu
DK
Chin
Department of Neurosurgery, The Spine and Spinal Cord Institute, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Keun Su
KS
Kim
Department of Neurosurgery, The Spine and Spinal Cord Institute, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Yong Eun
YE
Cho
Department of Neurosurgery, The Spine and Spinal Cord Institute, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea. kuhsu@yuhs.ac.
Sung Uk
SU
Kuh
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000097:blood*; D015519:Bone Density; D016723:Bone Remodeling; D001862:Bone Resorption; D024042:Collagen Type I / Q000378:metabolism; D005260:Female; D005269:Femur / Q000378:metabolism*; D006801:Humans; D008159:Lumbar Vertebrae / Q000378:metabolism; D008297:Male; D009919:Orchiectomy / Q000009:adverse effects*; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis; D010024:Osteoporosis / Q000378:metabolism; D010455:Peptides; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D055114:X-Ray Microtomography
D015415:Biomarkers; D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin; D000469:Alkaline Phosphatase
Osteoporosis; bone mineral density; femur; orchiectomy; spine