NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Steady and transient fluid shear stress stimulate NO release in osteoblasts through distinct biochemical pathwaysFluid flow has been shown to be a potent stimulus in osteoblasts and osteocytes and may therefore play an important role in load-induced bone remodeling. The objective of this study was to investigate the characteristics of flow-activated pathways. Previously we reported that fluid flow stimulates rapid and continuous release of nitric oxide (NO) in primary rat calvarial osteoblasts. Here we demonstrate that flow-induced NO release is mediated by shear stress and that this response is distinctly biphasic. Transients in shear stress associated with the onset of flow stimulated a burst in NO production (8.2 nmol/mg of protein/h), while steady flow stimulated sustained NO production (2.2 nmol/mg of protein/h). Both G-protein inhibition and calcium chelation abolished the burst phase but had no effect on sustained production. Activation of G-proteins stimulated dose-dependent NO release in static cultures of both calvarial osteoblasts and UMR-106 osteoblast-like cells. Pertussis toxin had no effect on NO release. Calcium ionophore stimulated low levels of NO production within 15 minutes but had no effect on sustained production. Taken together, these data suggest that fluid shear stress stimulates NO release by two distinct pathways: a G-protein and calcium-dependent phase sensitive to flow transients, and a G-protein and calcium-independent pathway stimulated by sustained flow.
Document ID
20040141941
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
McAllister, T. N.
(University of California-San Diego La Jolla, California 92093, United States)
Frangos, J. A.
Date Acquired
August 22, 2013
Publication Date
June 1, 1999
Publication Information
Publication: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research
Volume: 14
Issue: 6
ISSN: 0884-0431
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: HL-40696
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Cell Biology

Available Downloads

There are no available downloads for this record.
No Preview Available