Department of Restorative Dentistry and Endodontics, Faculty of Dentistry, Semmelweis University, H-1088 Budapest, Szentkirályi utca 47, Budapest, Hungary.
BMC Oral Health. 2024 Nov 17;24(1):1398. doi: 10.1186/s12903-024-05169-7.
This study investigates the dose-response relationship of acetylcholine (ACh) on healthy human gingival blood flow (GBF). Understanding this dose-response relationship contributes to studying vasodilatory mechanisms in various pathological conditions.
The study involved 22 young healthy men (21 - 32 years) to investigate the dose-response relationship of ACh on GBF. Semi-circular wells were created on the labial surface of the upper right second incisor (FDI #12) and upper left first incisor (FDI #21), including the gingival sulcus, for the application of drugs. ACh-chloride solutions at 0.1, 1, and 10 mg/mL were administered to the gingival sulcus of tooth FDI #12 with a Hamilton syringe. Physiological saline was applied on the contralateral side to FDI #21 as a control. The GBF was measured non-invasively by the laser speckle contrast imaging method in four 1mm high adjacent regions: coronal, midway1, midway2, and apical, and was expressed in a laser speckle perfusion unit (LSPU). After the baseline blood flow recording, ACh doses were applied sequentially, with washout periods in between. Data were statistically analyzed using a linear mixed model.
The GBF did not change on the saline site throughout the experiment. The GBF was significantly higher at the coronal region after all ACh doses (baseline: 218±31 LSPU, and 227±38 LSPU p < 0.05, 239±40 LSPU p < 0.001, 291±54 LSPU p < 0.001, respectively) compared to the saline. It was also elevated following 1 and 10 mg/mL at the midway1 (245±48 LSPU, p < 0.05, 293±65 LSPU p < 0.001). At midway2 and apical, only the 10 mg/mL dose was effective (285±71 LSPU, p < 0.001; 302±82 LSPU, p < 0.001).
Our findings suggest a dose-dependent vasodilation to ACh, emphasizing its role in human gingival microcirculation. Only the 10 mg/mL ACh could evoke remote vasodilation 3 mm from the application. The described method could facilitate the investigation of endothelium-dependent vasodilation in disorders affecting microcirculation, such as periodontitis or diabetes.
本研究旨在探讨乙酰胆碱（ACh）对健康人牙龈血流（GBF）的剂量反应关系。了解这种剂量反应关系有助于研究各种病理情况下的血管扩张机制。
本研究纳入了 22 名年轻健康男性（21-32 岁），以探讨 ACh 对 GBF 的剂量反应关系。在上颌右侧第二前磨牙（FDI#12）和左上第一前磨牙（FDI#21）的唇面创建半圆形小凹，包括龈沟，用于药物应用。用 Hamilton 注射器将 0.1、1 和 10mg/mL 的 ACh 氯化物溶液注入 FDI#12 的龈沟。在 FDI#21 的对侧应用生理盐水作为对照。通过激光散斑对比成像方法无创测量四个相邻 1mm 高区域（冠部、中 1 部、中 2 部和根尖部）的 GBF，并以激光散斑灌注单位（LSPU）表示。在基线血流记录后，依次应用 ACh 剂量，并在每个剂量之间进行冲洗。使用线性混合模型对数据进行统计分析。
整个实验过程中，生理盐水部位的 GBF 没有变化。与生理盐水相比，所有 ACh 剂量后，冠部的 GBF 均显著升高（基线：218±31 LSPU，227±38 LSPU p<0.05，239±40 LSPU p<0.001，291±54 LSPU p<0.001）。在中 1 部也升高，1mg/mL 和 10mg/mL 剂量分别为 245±48 LSPU（p<0.05）和 293±65 LSPU（p<0.001）。在中 2 部和根尖部，只有 10mg/mL 剂量有效（285±71 LSPU，p<0.001；302±82 LSPU，p<0.001）。
我们的发现表明 ACh 存在剂量依赖性血管扩张，强调了其在人类牙龈微循环中的作用。只有 10mg/mL 的 ACh 可以诱发距应用部位 3mm 处的远程血管扩张。所描述的方法可以促进对影响微循环的疾病（如牙周炎或糖尿病）中内皮依赖性血管扩张的研究。
