A non-invasive, in vivo model for mechanically induced stimulation of the tibia of rats will be used to further define the response of cortical bone to mechanical loads. Specifically, the study will focus on the bone modeling response of the tibia to mechanical bending. It is anticipated that the modeling response will be either lamellar or woven bone formation on the periosteal and endosteal surfaces. This study has six major objectives 1) to determine the number of cycles per day of mechanical stimuli that cause lamellar bone formation and the number that cause woven bone formation, 2) to determine the mechanism of increase of lamellar bone formation in response to increasing mechanical stimulus, 3) to quantify the stress/strain signals in the bone and correlate their magnitudes to the bone formation response after 12 days, 4) to demonstrate the effects of blocking prostaglandin synthesis on adaptive bone modeling, 5) to find the time needed for rat bones to fully adapt to mechanical bending, and 6) to quantify the stress/strain signals in fully adapted bone and correlate their magnitudes with their initial magnitudes before adaption took place. This study uses the engineering methods of finite element analysis, beam bending analysis, and in vivo strain gage measurements to quantify the stress/strain signals created by bending the tibia. Histomorphometry of fluorochrome bone labels will be used to quantify the new bone formation.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
7R29AR040688-02
Application #
3457486
Study Section
Experimental Cardiovascular Sciences Study Section (ECS)
Project Start
1991-05-01
Project End
1995-12-31
Budget Start
1991-06-25
Budget End
1991-12-31
Support Year
2
Fiscal Year
1991
Total Cost
Indirect Cost
Name
Indiana University-Purdue University at Indianapolis
Department
Type
Schools of Medicine
DUNS #
005436803
City
Indianapolis
State
IN
Country
United States
Zip Code
46202
Takano, Y; Turner, C H; Owan, I et al. (1999) Elastic anisotropy and collagen orientation of osteonal bone are dependent on the mechanical strain distribution. J Orthop Res 17:59-66
Akhter, M P; Cullen, D M; Pedersen, E A et al. (1998) Bone response to in vivo mechanical loading in two breeds of mice. Calcif Tissue Int 63:442-9
Turner, C H; Owan, I; Alvey, T et al. (1998) Recruitment and proliferative responses of osteoblasts after mechanical loading in vivo determined using sustained-release bromodeoxyuridine. Bone 22:463-9
Pidaparti, R M; Turner, C H (1997) Cancellous bone architecture: advantages of nonorthogonal trabecular alignment under multidirectional joint loading. J Biomech 30:979-83
Turner, C H; Owan, I; Jacob, D S et al. (1997) Effects of nitric oxide synthase inhibitors on bone formation in rats. Bone 21:487-90
Turner, C H; Anne, V; Pidaparti, R M (1997) A uniform strain criterion for trabecular bone adaptation: do continuum-level strain gradients drive adaptation? J Biomech 30:555-63
Forwood, M R; Owan, I; Takano, Y et al. (1996) Increased bone formation in rat tibiae after a single short period of dynamic loading in vivo. Am J Physiol 270:E419-23
Pidaparti, R M; Chandran, A; Takano, Y et al. (1996) Bone mineral lies mainly outside collagen fibrils: predictions of a composite model for osteonal bone. J Biomech 29:909-16
Takano, Y; Turner, C H; Burr, D B (1996) Mineral anisotropy in mineralized tissues is similar among species and mineral growth occurs independently of collagen orientation in rats: results from acoustic velocity measurements. J Bone Miner Res 11:1292-301
Turner, C H; Takano, Y; Owan, I et al. (1996) Nitric oxide inhibitor L-NAME suppresses mechanically induced bone formation in rats. Am J Physiol 270:E634-9

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