[Effect of radiation on the activity and expression of Ca(2+)-Mg(2+)-ATPase in rat masseter muscle].
OBJECTIVE
To investigate the activity and expression of Ca(2+)-Mg(2+)-ATPase in irradiated rat masseter muscle.


METHODS
The rats were irradiated locally with a single dose of 20 Gy X-ray. The activities of Ca(2+)-Mg(2+)-ATPase were measured with colorimetric method. The protein expression of Ca(2+)-Mg(2+)-ATPase was determined by Western blotting and immunohistochemistry.


RESULTS
The activities of Ca(2+)-Mg(2+)-ATPase in masseter muscle decreased by approximately 20% and 40% in irradiated rats on days 3 and 30 postirradiation. There was significant difference in the expression of Ca(2+)-Mg(2+)-ATPase protein between irradiated and nonirradiated rats on day 30 postirradiation. Ca(2+)-Mg(2+)-ATPase protein was found in the cytoplasm of masseter muscle.


CONCLUSIONS
The decrease of ATPase activity played an important role in the cause of radiation-induced skeletal muscle injury, while there was no significant reduction in the expression of Ca(2+)-Mg(2+)-ATPase protein in irradiated rat masseter muscle.
Li
Zhi-Min
ZM
Department of Oral Radiology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
Ma
Xu-Chen
XC
Qu
Xing-Min
XM
Xu
Shou-Ping
SP
Ma
Lin
L
D000818:Animals; D015153:Blotting, Western; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D003593:Cytoplasm / Q000201:enzymology; D007150:Immunohistochemistry; D008406:Masseter Muscle / Q000201:enzymology / Q000528:radiation effects*; D011833:Radiation Injuries, Experimental / Q000201:enzymology*; D051381:Rats
D017301:Ca(2+) Mg(2+)-ATPase