Department of Morphology, Division of Histology, Piracicaba Dental School, State University of Campinas, Piracicaba, São Paulo, Brazil.
Acta Histochem. 2013 Apr;115(3):245-51. doi: 10.1016/j.acthis.2012.07.002. Epub 2012 Aug 13.
Matrix metalloproteinases (MMPs) in dentin are believed to participate in various physiological and pathological events in coronal dentin, but their exact source and location is not clear. The purpose of this study was to evaluate the activity of gelatinases in decalcified rat molars crowns by in situ zymography. Hemi-mandibles of five male Wistar rats were fixed in paraformaldehyde, decalcified in EDTA and glycerol solution and embedded in paraffin. Sections from the region of molar teeth were incubated with or without DQ gelatin in 50mM Tris-CaCl2 at 37°C for 2h and observed by means of confocal microscopy. Gelatinolytic activity was observed throughout the coronal dentin with varying intensities in different locations. High gelatinase activity was observed in the dentinal tubules, dentin-enamel junction (DEJ) and predentin, and it was weaker and less uniform in the intertubular dentin. This study shows that the location of gelatinase and relative activity can be detected by means of in situ zymography and confocal microcopy, and this methodology may provide a useful tool in studies on the role of gelatinases in tooth development, maturation and in pathological conditions.
牙本质中的基质金属蛋白酶（MMPs）被认为参与了冠向牙本质中的各种生理和病理事件，但它们的确切来源和位置尚不清楚。本研究旨在通过原位酶谱法评估脱钙大鼠磨牙冠部明胶酶的活性。将五只雄性 Wistar 大鼠的半下颌骨用多聚甲醛固定，用 EDTA 和甘油溶液脱钙，然后包埋在石蜡中。将来自磨牙区域的切片在 37°C 下在含有或不含有 DQ 明胶的 50mM Tris-CaCl2 中孵育 2 小时，并通过共聚焦显微镜进行观察。在牙本质的整个冠部都观察到了明胶酶活性，不同部位的强度不同。在牙本质小管、牙釉质牙本质交界处（DEJ）和前期牙本质中观察到高明胶酶活性，而在管间牙本质中活性较弱且均匀性较差。本研究表明，通过原位酶谱法和共聚焦显微镜可以检测明胶酶的位置和相对活性，这种方法可能为研究明胶酶在牙齿发育、成熟和病理条件下的作用提供有用的工具。
