Abstract：
This study had the aim of examining the relationships between variations in estrogen levels resulting from ovariectomy, and estrogen hormone replacement therapy (HRT) in rats subjected to an orofacial inflammatory pain model. Eighty adult female Wistar rats were initially divided into 2 groups: Sham or ovariectomy (OVX-D1). Seven days later (D7), the rats were subjected to an unilateral infiltration of Freund\'s Complete Adjuvant (CFA) or saline solution into the right temporomandibular joint (TMJ). Then, rats received 17β-estradiol (28 µg/kg/day) or placebo for 21 days (D10-D31). Nociception was evaluated by the von Frey (VF) and the Hot Plate (HP) tests, and depressive-like behavior by the Forced Swimming (FS) test. On D32 all rats were euthanized and serum, hippocampus and brainstem were collected. The CFA groups presented a mechanical hyperalgesia until day 21 (p ≤ 0.05). No differences were observed among groups in the HP (p = 0.735), and in the immobility and swimming time of the FS (p = 0.800; p = 0.998, respectively). In the brainstem, there was a significant difference in the TNF-ɑ levels (p = 0.043), and a marginal significant difference in BDNF levels (p = 0.054), without differences among groups in the hippocampal BDNF and TNF-ɑ levels (p = 0.232; p = 0.081, respectively). In conclusion, the hormone replacement therapy did not alleviate orofacial pain in ovariectomized rats. However, there is a decrease in brainstem TNF-ɑ levels in the animals submitted to both models, which was partially reverted by HRT.
摘要：
这项研究的目的是检查卵巢切除术导致的雌激素水平变化之间的关系。和雌激素替代治疗（HRT）在大鼠的口面炎性疼痛模型。80只成年雌性Wistar大鼠最初分为2组：假手术或卵巢切除术（OVX-D1）。七天后（D7），大鼠接受弗氏完全佐剂(CFA)或盐水溶液单侧浸润至右侧颞下颌关节(TMJ).然后，大鼠接受17β-雌二醇(28µg/kg/天)或安慰剂21天(D10-D31).通过vonFrey（VF）和热板（HP）测试评估伤害感受，通过强迫游泳(FS)测试，以及类似抑郁的行为。在D32上，所有大鼠均被安乐死并血清，收集海马和脑干。CFA组出现机械性痛觉过敏，直至第21天（p≤0.05）。在HP组间没有观察到差异（p=0.735），以及FS的不动和游泳时间（分别为p=0.800；p=0.998）。在脑干，TNF-α水平差异有统计学意义(p=0.043),BDNF水平有边际显著差异(p=0.054)，各组间海马BDNF和TNF-α水平无差异(p=0.232;p=0.081)。总之,激素替代疗法不能缓解去卵巢大鼠的口面部疼痛。然而,两种模型动物的脑干TNF-α水平均下降，HRT部分还原了。
