Postgraduate Program in Dentistry, Department of Dentistry, University of Taubaté, Taubaté, SP, Brazil.
J Appl Oral Sci. 2011 Apr;19(2):113-7. doi: 10.1590/s1678-77572011000200006.
Nitric oxide (NO) has been considered a key molecule in inflammation.
The aim of this study was to evaluate the effect of treatment with L-NAME and sodium nitroprussiate, substances that inhibit and release NO, respectively, on tissue tolerance to endodontic irrigants.
The vital dye exudation method was used in a rat subcutaneous tissue model. Injections of 2% Evans blue were administered intravenously into the dorsal penial vein of 14 male rats (200-300 g). The NO inhibitor and donor substances were injected into the subcutaneous tissue in the dorsal region, forming two groups of animals: G1 was inoculated with L-NAME and G2 with sodium nitroprussiate. Both groups received injections of the test endodontic irrigants: acetic acid, 15% citric acid, 17% EDTA-T and saline (control). After 30 min, analysis of the extravasated dye was performed by light absorption spectrophotometry (620 nm).
There was statistically significant difference (p<0.05) between groups 1 and 2 for all irrigants. L-NAME produced a less intense inflammatory reaction and nitroprussiate intensified this process.
Independently of the administration of NO inhibitors and donors, EDTA-T produced the highest irritating potential in vital tissue among the tested irrigating solutions.
一氧化氮（NO）被认为是炎症的关键分子。
本研究旨在评估分别抑制和释放 NO 的 L-NAME 和硝普酸钠治疗对牙髓冲洗剂组织耐受性的影响。
在大鼠皮下组织模型中使用活染料渗出法。将 2% Evans 蓝静脉内注射到 14 只雄性大鼠（200-300g）的阴茎背侧静脉。NO 抑制剂和供体物质注入背侧皮下组织，形成两组动物：G1 接种 L-NAME，G2 接种硝普酸钠。两组均接受测试牙髓冲洗剂注射：乙酸、15%柠檬酸、17% EDTA-T 和生理盐水（对照）。30 分钟后，通过分光光度法（620nm）分析渗出染料。
对于所有冲洗剂，组 1 和组 2 之间存在统计学显著差异（p<0.05）。L-NAME 产生的炎症反应较弱，硝普酸钠则加剧了这一过程。
无论是否给予 NO 抑制剂和供体，EDTA-T 在测试的冲洗液中对活组织产生的刺激性最强。
