[Protective effect of meloxicam against acute radiation-induced brain injury in rats].
OBJECTIVE To observe the protective effect of meloxicam against acute radiation-induced brain injury in rats.


METHODS
Fifty-four SD rats were randomly divided into blank control group, radiation group (20 Gy) and therapy group (20 Gy radiation followed by 10 mg/kg meloxicam treatment). The whole brain of SD rats in the radiation and therapy groups were vertically irradiated by 6 MeV electron beam at a dose of 20 Gy. One, 3 and 7 days after irradiation, the morphological changes of hippocampal neurons were observed using HE staining, and the expressions of cyclooxygenase-2 (COX-2) mRNA and protein were detected by RT-PCR and immunohistochemistry, respectively.


RESULTS
Compared with the blank control group, the radiation group showed that the neuron swelling and vascular endothelial cell edema as well as space enlargement around the capillaries. Both neuron swelling and vascular endothelial cell injury in the therapy group were slighter than those in the radiation group. Compared with the blank control group, the levels of COX-2 mRNA and protein in the radiation and therapy groups increased obviously one day after irradiation (P<0.05), and compared with the radiation group, the levels decreased obviously in the therapy group (P<0.05); 3 and 7 days after irradiation, the levels of COX-2 mRNA and protein among the 3 groups had no statistical differences (P>0.05).


CONCLUSIONS
The early use of meloxicam can reduce the brain injury induced by radiation. Its protective effect may be related to the relief of vascular endothelial cell injury and the decreased expression of COX-2.
Department of Oncology, First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, China.
Lan
L
Han
Qinglan
Q
Ren
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D001930:Brain Injuries / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D051546:Cyclooxygenase 2 / Q000235:genetics; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D008297:Male; D000077239:Meloxicam; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011833:Radiation Injuries, Experimental / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013843:Thiazines / Q000494:pharmacology*; D013844:Thiazoles / Q000494:pharmacology*
D016861:Cyclooxygenase Inhibitors; D012333:RNA, Messenger; D011837:Radiation-Protective Agents; D013843:Thiazines; D013844:Thiazoles; D051546:Cyclooxygenase 2; D000077239:Meloxicam