Bencivenni Davide, Neiders Mirdza E, Andreana Sebastiano, Moffitt Michelle L, Cohen Robert E
School of Dental Medicine, University of Modena and Reggio Emilia, Modena, Italy.
J Int Acad Periodontol. 2012 Jan;14(1):1-6.
Nifedipine, a calcium channel-blocking agent, has been associated with gingival enlargement in humans. This enlargement has also been successfully established in animal models. Previous investigators have administered nifedipine through a systemic route, most commonly by oral intake. The aim of the present study was to measure the effects of nifedipine administered directly into rat gingival interproximal papillae.
Twenty-four adult female rats were assigned to three groups. Each animal received a series of three injections, one week apart; each injection was placed directly into the interdental papilla of the maxillary and mandibular central incisors. Group 1 (control) received only saline. Group 2 received a low (10 microg/ml) concentration of nifedipine, while Group 3 received a higher concentration (500 microg/ml). One week after the last series of injections, gingival specimens were harvested from the injection site and prepared for histological and immunocytochemical analyses.
Specimens from Group 3 displayed a significantly greater number of ED2-positive cells compared to the other two groups. Specimens from Group 2 showed a significantly higher mean count of positive cells compared to Group 1. Collectively, our data suggest that repeated local injections of 10 microg/ml and 500 microg/ml nifedipine each elicit an inflammatory response in the gingival connective tissue.
Immunocytochemical analysis revealed dose-dependent increases of resident tissue macrophages in rats receiving nifedipine (p<0.005). An increased inflammatory infiltrate also was observed via routine histology. Gross macroscopic changes consistent with gingival enlargement were not observed.
硝苯地平作为一种钙通道阻滞剂，与人类牙龈增生有关。这种增生在动物模型中也已成功得到证实。既往研究者通过全身途径给药硝苯地平，最常见的是口服。本研究的目的是测定直接注射到大鼠牙龈邻间隙乳头中的硝苯地平的作用。
将24只成年雌性大鼠分为三组。每只动物接受一系列三次注射，每次注射间隔一周；每次注射均直接注入上颌和下颌中切牙的牙间乳头。第1组（对照组）仅接受生理盐水。第2组接受低浓度（10微克/毫升）的硝苯地平，而第3组接受高浓度（500微克/毫升）。在最后一系列注射后一周，从注射部位采集牙龈标本，准备进行组织学和免疫细胞化学分析。
与其他两组相比，第3组标本显示ED2阳性细胞数量显著更多。与第1组相比，第2组标本显示阳性细胞的平均计数显著更高。总体而言，我们的数据表明，重复局部注射10微克/毫升和500微克/毫升的硝苯地平均会在牙龈结缔组织中引发炎症反应。
免疫细胞化学分析显示，接受硝苯地平的大鼠体内驻留组织巨噬细胞呈剂量依赖性增加（p<0.005）。通过常规组织学检查也观察到炎症浸润增加。未观察到与牙龈增生一致的明显宏观变化。
