Effect of ovariectomy on bone response to in vivo external loading

H. Hagino, D. M. Raab, D. B. Kimmel, Mohammed P. Akhter, Robert R. Recker

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

This study was undertaken to find whether the bone response to increased external loading (EL) of the tibia in rats is affected by estrogen depletion. Female Sprague-Dawley rats 6 months were randomly assigned to four groups of 10 each: sham ovariectomy without loading (Shm-XL), ovariectomy without loading (OVX-XL), sham ovariectomy with external loading (Shm-EL), and ovariectomy with external loading (OVX-EL). In vivo external loading by a four-point bending device was initiated 4 weeks after surgery. The right lower leg of each EL rat was loaded at 31.4 ± 0.2 N for 36 cycles at 2 Hz every other day for 21 days (11 loading days). Mean in vivo induced strain was 1305 microstrain (με) for Shm-EL rats and 1280με for OVX-EL rats. With external loading of the tibia, periosteal bone formation rose equally in Shm and OVX rats. Woven bone was present around the tibia or fibula in 60% of the loaded rats and none of the control rats. No loading response occurred either at the endocortical surface or in the cancellous bone of the proximal tibial metaphysis. After OVX, cancellous bone area in the proximal metaphysis declined and formation surface rose compared to Shm rats. Although periosteal and endocortical bone formation rose after OVX, no cortical bone loss occurred. We conclude that ovariectomy and attendant loss of endogenous estrogen do not change the cortical bone response to an external load of about 1300με in rats. However, these results may not predict the cortical bone response to loading in animals with Haversian remodeling that display estrogen-related loss of cortical bone.

Original languageEnglish
Pages (from-to)347-357
Number of pages11
JournalJournal of Bone and Mineral Research
Volume8
Issue number3
StatePublished - 1993

Fingerprint

Ovariectomy
Bone and Bones
Tibia
Estrogens
Osteogenesis
Fibula
Sprague Dawley Rats
Leg
Equipment and Supplies
Cortical Bone

All Science Journal Classification (ASJC) codes

  • Surgery

Cite this

Effect of ovariectomy on bone response to in vivo external loading. / Hagino, H.; Raab, D. M.; Kimmel, D. B.; Akhter, Mohammed P.; Recker, Robert R.

In: Journal of Bone and Mineral Research, Vol. 8, No. 3, 1993, p. 347-357.

Research output: Contribution to journalArticle

@article{0a8a15e7179d4051865145b4d0ab6da6,
title = "Effect of ovariectomy on bone response to in vivo external loading",
abstract = "This study was undertaken to find whether the bone response to increased external loading (EL) of the tibia in rats is affected by estrogen depletion. Female Sprague-Dawley rats 6 months were randomly assigned to four groups of 10 each: sham ovariectomy without loading (Shm-XL), ovariectomy without loading (OVX-XL), sham ovariectomy with external loading (Shm-EL), and ovariectomy with external loading (OVX-EL). In vivo external loading by a four-point bending device was initiated 4 weeks after surgery. The right lower leg of each EL rat was loaded at 31.4 ± 0.2 N for 36 cycles at 2 Hz every other day for 21 days (11 loading days). Mean in vivo induced strain was 1305 microstrain (με) for Shm-EL rats and 1280με for OVX-EL rats. With external loading of the tibia, periosteal bone formation rose equally in Shm and OVX rats. Woven bone was present around the tibia or fibula in 60{\%} of the loaded rats and none of the control rats. No loading response occurred either at the endocortical surface or in the cancellous bone of the proximal tibial metaphysis. After OVX, cancellous bone area in the proximal metaphysis declined and formation surface rose compared to Shm rats. Although periosteal and endocortical bone formation rose after OVX, no cortical bone loss occurred. We conclude that ovariectomy and attendant loss of endogenous estrogen do not change the cortical bone response to an external load of about 1300με in rats. However, these results may not predict the cortical bone response to loading in animals with Haversian remodeling that display estrogen-related loss of cortical bone.",
author = "H. Hagino and Raab, {D. M.} and Kimmel, {D. B.} and Akhter, {Mohammed P.} and Recker, {Robert R.}",
year = "1993",
language = "English",
volume = "8",
pages = "347--357",
journal = "Journal of Bone and Mineral Research",
issn = "0884-0431",
publisher = "Wiley-Blackwell",
number = "3",

}

TY - JOUR

T1 - Effect of ovariectomy on bone response to in vivo external loading

AU - Hagino, H.

AU - Raab, D. M.

AU - Kimmel, D. B.

AU - Akhter, Mohammed P.

AU - Recker, Robert R.

PY - 1993

Y1 - 1993

N2 - This study was undertaken to find whether the bone response to increased external loading (EL) of the tibia in rats is affected by estrogen depletion. Female Sprague-Dawley rats 6 months were randomly assigned to four groups of 10 each: sham ovariectomy without loading (Shm-XL), ovariectomy without loading (OVX-XL), sham ovariectomy with external loading (Shm-EL), and ovariectomy with external loading (OVX-EL). In vivo external loading by a four-point bending device was initiated 4 weeks after surgery. The right lower leg of each EL rat was loaded at 31.4 ± 0.2 N for 36 cycles at 2 Hz every other day for 21 days (11 loading days). Mean in vivo induced strain was 1305 microstrain (με) for Shm-EL rats and 1280με for OVX-EL rats. With external loading of the tibia, periosteal bone formation rose equally in Shm and OVX rats. Woven bone was present around the tibia or fibula in 60% of the loaded rats and none of the control rats. No loading response occurred either at the endocortical surface or in the cancellous bone of the proximal tibial metaphysis. After OVX, cancellous bone area in the proximal metaphysis declined and formation surface rose compared to Shm rats. Although periosteal and endocortical bone formation rose after OVX, no cortical bone loss occurred. We conclude that ovariectomy and attendant loss of endogenous estrogen do not change the cortical bone response to an external load of about 1300με in rats. However, these results may not predict the cortical bone response to loading in animals with Haversian remodeling that display estrogen-related loss of cortical bone.

AB - This study was undertaken to find whether the bone response to increased external loading (EL) of the tibia in rats is affected by estrogen depletion. Female Sprague-Dawley rats 6 months were randomly assigned to four groups of 10 each: sham ovariectomy without loading (Shm-XL), ovariectomy without loading (OVX-XL), sham ovariectomy with external loading (Shm-EL), and ovariectomy with external loading (OVX-EL). In vivo external loading by a four-point bending device was initiated 4 weeks after surgery. The right lower leg of each EL rat was loaded at 31.4 ± 0.2 N for 36 cycles at 2 Hz every other day for 21 days (11 loading days). Mean in vivo induced strain was 1305 microstrain (με) for Shm-EL rats and 1280με for OVX-EL rats. With external loading of the tibia, periosteal bone formation rose equally in Shm and OVX rats. Woven bone was present around the tibia or fibula in 60% of the loaded rats and none of the control rats. No loading response occurred either at the endocortical surface or in the cancellous bone of the proximal tibial metaphysis. After OVX, cancellous bone area in the proximal metaphysis declined and formation surface rose compared to Shm rats. Although periosteal and endocortical bone formation rose after OVX, no cortical bone loss occurred. We conclude that ovariectomy and attendant loss of endogenous estrogen do not change the cortical bone response to an external load of about 1300με in rats. However, these results may not predict the cortical bone response to loading in animals with Haversian remodeling that display estrogen-related loss of cortical bone.

UR - http://www.scopus.com/inward/record.url?scp=0027474550&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027474550&partnerID=8YFLogxK

M3 - Article

C2 - 8456589

AN - SCOPUS:0027474550

VL - 8

SP - 347

EP - 357

JO - Journal of Bone and Mineral Research

JF - Journal of Bone and Mineral Research

SN - 0884-0431

IS - 3

ER -