Rose R K, Turner S J
MRC Dental Group, Dental School, Bristol, UK.
Biochim Biophys Acta. 1998 Feb 2;1379(2):185-90. doi: 10.1016/s0304-4165(97)00098-6.
Diffusion, which limits nutrient penetration and end-product export in biofilms, is restricted by reversible binding and extracellular volume fraction (Ve). Fluoride has been demonstrated to prevent calcium bridging, hence inhibiting calcium-mediated cell association (Rose, Lee and Shellis, Caries Res. 30 (1996) 458-464). 3H-inulin effusion measurements from streptococcal model plaques, at pH 7.0 or 5.0, 0-20 mmol/l Ca2+, and with or without 5 mmol/l KF, demonstrated that Ve was greatest in the absence of added Ca2+ and at pH 7.0, lowest at 20 mmol/l Ca2+ and pH 5.0, and that F- raised the minimum Ve. By bridging adjacent cells and reducing the net negative charge, calcium and low pH, respectively, reduce Ve. Fluoride eliminates the calcium-bridging effect, hence increasing Ve.
扩散限制了生物膜中营养物质的渗透和终产物的输出，它受到可逆结合和细胞外体积分数（Ve）的限制。已证明氟化物可防止钙桥形成，从而抑制钙介导的细胞结合（罗斯、李和谢利斯，《龋病研究》30（1996）458 - 464）。在pH值为7.0或5.0、Ca2+浓度为0 - 20 mmol/L、添加或不添加5 mmol/L KF的条件下，对链球菌模型菌斑进行3H - 菊粉渗出测量，结果表明，在不添加Ca2+且pH值为7.0时Ve最大，在Ca2+浓度为20 mmol/L且pH值为5.0时Ve最小，并且F - 提高了Ve的最小值。钙和低pH值分别通过桥接相邻细胞和减少净负电荷来降低Ve。氟化物消除了钙桥接效应，从而增加了Ve。
