Nitric oxide inhibitor l-name suppresses mechanically-induced bone
formation in rats.
Turner, Charles H., Yuichi Takano, and Ichiro Owan, George A. C.
Murrell.
Department of Orthopaedic Surgery and The Biomechanics and
Biomaterials Research Center, Indiana University Medical Center,
Indianapolis, IN 46202, USA, The Hospital for Special Surgery,
Cornell University Medical College, 535 East 70th Street, New York,
NY 10021, USA
APStracts 2:0232E, 1995.
We hypothesized that nitric oxide may act as an intermediary in the
transduction of mechanical loading of bone into a bone formation
response. In the present study, 48 rats were divided into three
treatment groups: control, treatment with Nw-nitro-L-arginine methyl
ester or L-NAME (an inhibitor of nitric oxide synthase), and
treatment with D-NAME (the less active enantiomer of L-NAME). The
rats were subdivided into groups subjected to four-point bending or
sham loading of their right tibiae. Bone formation was measured at
the midshaft of the loaded and nonloaded (left) tibiae of each rat
using histomorphometric methods. The application of four-point
bending, but not sham loading, resulted in new bone formation.
Treatment with L-NAME reduced the rate of mechanically-induced bone
formation by 3-fold compared to the control group. Bone formation
rates in nonloaded or sham-loaded limbs were not affected by L-NAME
treatment. The results suggest that nitric oxide may play a role in
the transduction of a mechanical stimulus into a biological response
in bone.
Received 5 June 1995; accepted in final form 2 November 1995.
APS Manuscript Number E255-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95