Table 1:

Bone Phenotypes of NO Synthase-deficient mice

Global Knockout	Bone Phenotype	Histomorphometry	In vitro Studies	References
NOS-1 −/−	Osteosclerosis, increased BMD	Increased BV/TV, trabecular and cortical thickness, OC number Decreased OB number, MAR & BFR	Increased OC size & number, decreased resorption	27,28
NOS-2 −/−	No obvious bone phenotype at baseline, Decreased reloading-induced osteogenesis	Normal BV/TV, BFR, OC number	OC: enhanced RANKL-induced differentiation	13,29
NOS-3 −/−	Reduced bone length & bone volumes, reduced BMD (only up to 8-10 weeks of age?) Decreased osteogenesis in response to fluid shear (venous ligation) More bone loss after OVX and blunted response to estrogens	Reduced BV/TV, trabecular number, BFR & MAR, OB number (normal OC number)	Defects in chondrocyte and OB proliferation, defects in OB differentiation	12,30-36