Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, SP, Brazil.
Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University (Unesp), São José dos Campos, SP, Brazil.
Arch Oral Biol. 2020 Feb;110:104590. doi: 10.1016/j.archoralbio.2019.104590. Epub 2019 Oct 20.
To investigate the influence of chronic stress and adrenergic blockade in a rat model of apical periodontitis.
Thirty-two Wistar rats were submitted to an animal model of periapical lesion and randomly divided into 4 groups (n = 8): no stress (NS); stress + saline solution (SS); stress + β-adrenergic blocker (Sβ); stress + α-adrenergic blocker (Sα). The SS, Sβ and Sα groups were submitted to an animal model of chronic stress for 28 days and received daily injections of saline solution, propranolol (β adrenergic blocker) and phentolamine (α adrenergic blocker), respectively. After 28 days the animals were euthanized and the following analyses were carried out: a) serum corticosterone levels through Radioimmunoassay; b) measurement of serum levels of IL-1B, IL-6, IL-10 and IL-17 by enzyme-linked immunosorbent assay (ELISA); c) volume of periapical bone resorption by micro-computed tomography; d) histomorphometric analysis by staining with hematoxylin and eosin; e) expression of β-AR, α-AR, receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) by immunohistochemistry; f) tartrate-resistant acid phosphatase (TRAP) staining; g) ex-vivo cytokine release followed by the stimulation with LPS in superfusion system, by ELISA.
SS group displayed significantly higher corticosterone levels than NS group (non-stressed). Higher IL-1β serum level was observed in the NS group (p < .05); compared to all stressed groups. Other cytokines were present in similar amounts in the serum of all groups. All groups presented similar periapical lesions. All groups presented moderate inflammatory infiltrate, without statistically significant differences between them. No differences were observed regarding β-AR, α-AR, Rank-L and OPG expression. The number of TRAP-positive cells was significantly decreased in the groups that received daily injections of adrenergic blockers. The IL-1β release followed LPS stimulation was significantly suppressed when the superfusion media contained propranolol (p < .05). Perfusion containing phentolamine induced a greater release of IL-10. TGF-β was significantly suppressed by phentolamine perfusion in the NS group (p < .05).
Chronic stress can significantly change the inflammatory cytokines release. Rank-L/OPG system and periapical lesion volume were not affected following the current method applied. The administration of adrenergic blockers was not able to modulate the inflammatory response but presented effectivity in reducing the number of osteoclasts in the periapical region.
研究慢性应激和肾上腺素能阻断在大鼠根尖周炎模型中的影响。
32 只 Wistar 大鼠被置于根尖病变动物模型中，并随机分为 4 组（n=8）：无应激（NS）；应激+生理盐水溶液（SS）；应激+β-肾上腺素能阻滞剂（Sβ）；应激+α-肾上腺素能阻滞剂（Sα）。SS、Sβ 和 Sα 组接受 28 天的慢性应激动物模型，并分别接受每日生理盐水、普萘洛尔（β 肾上腺素能阻滞剂）和苯氧苄胺（α 肾上腺素能阻滞剂）注射。28 天后，处死动物并进行以下分析：a）通过放射免疫法检测血清皮质酮水平；b）通过酶联免疫吸附试验（ELISA）测量血清白细胞介素-1B（IL-1B）、白细胞介素-6（IL-6）、白细胞介素-10（IL-10）和白细胞介素-17（IL-17）水平；c）通过微计算机断层扫描测量根尖骨吸收体积；d）通过苏木精和伊红染色进行组织形态计量学分析；e）通过免疫组织化学法检测β-AR、α-AR、核因子 kappa-B 配体受体激活剂（RANKL）和骨保护素（OPG）的表达；f）抗酒石酸酸性磷酸酶（TRAP）染色；g）通过 ELISA 在体外细胞因子释放后，通过 LPS 在灌流系统中进行刺激。
SS 组的皮质酮水平明显高于 NS 组（无应激）。在 NS 组中观察到血清中 IL-1β 水平较高（p<0.05）；与所有应激组相比。所有组的血清中均存在相似数量的其他细胞因子。所有组均表现出相似的根尖病变。所有组均表现出中度炎症浸润，但组间无统计学差异。β-AR、α-AR、Rank-L 和 OPG 的表达无差异。接受每日肾上腺素能阻滞剂注射的组中，TRAP 阳性细胞数明显减少。当灌流介质中含有普萘洛尔时，IL-1β 释放受到 LPS 刺激的抑制作用显著（p<0.05）。含苯氧苄胺的灌流诱导 IL-10 释放增加。在 NS 组中，苯氧苄胺灌流显著抑制 TGF-β（p<0.05）。
慢性应激可显著改变炎症细胞因子的释放。在目前应用的方法下，Rank-L/OPG 系统和根尖病变体积不受影响。肾上腺素能阻滞剂的给药不能调节炎症反应，但在减少根尖区破骨细胞数量方面具有有效性。
