[The effect of fluid shear stress on the proliferation of rat primary osteoblast-like cells in vitro].
OBJECTIVE
To inquire into the cellular mechanism by which mechanical stress regulates bone remodeling and make an attempt at establishing the most suitable physiological stress to stimulate bone formation.


METHODS
The isolated rat primary osteoblast-like cells were exposed to fluid shear stress 2, 4, 8, 12, 14, 17 and 19 dyn/cm2 for 60 min respectively in the flow chamber. The ability of proliferation of cells was studied by flow cytometry.


RESULTS
After exposed to fluid shear stress, the cells rearranged and the cells' axes were elongated following the flow direction. The proliferation indexes (PI) of the cells went up with the gradual increase of shear stress. When fluid stress reached 12 dyn/cm2, the PI of cells increased significantly (P < 0.05), compared with the control. But the PI of cells began to decrease when the fluid stress continued to increase, and when fluid stress reached 14 dyn/cm2, the PI of cells decreased significantly (P < 0.01), compared with the control.


CONCLUSIONS
The mechanism by which mechanical stress regulates bone remodeling is related to the proliferation of the osteoblast cells stimulated by stress-induced fluid flow. Low shear stress has no marked influence on the proliferation of cells. Medium shear stress (12 dyn/cm2) can stimulate cells significantly. Major shear stress (14 dyn/cm2) can inhibit cells significantly.
Chen
W
W
School of Stomatology, WCUMS, Chengdu 610041, China.
Qiao
J
J
Luo
S
S
Li
S
S
Tian
W
W
Li
P
P
D000818:Animals; D000831:Animals, Newborn; D016723:Bone Remodeling; D002455:Cell Division; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D010006:Osteoblasts / Q000166:cytology*; D051381:Rats; D013314:Stress, Mechanical
D004247:DNA