Study of regulation of acid excretion from the cells of plaque bacteria

牙菌斑细菌细胞排酸调控的研究

基本信息

批准号：
07672009
负责人：
IWAMI Yoshimichi
金额：
$ 1.22万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07672009/
关键词：
Proton-ATPase Potassium ion Sodium ion Fluoride Intracellular pH Acid production Streptococcus Streptococus Streptococcus mutans

项目摘要

(1). The effect of sodium and potassium ions on intracellular acid production and acid excretion by glycolyzing cells of Streptococcus mutans was examined. A pH-sensitive fluorescent dye, bis (carboxyethyl)-carboxyfluorescein allowed for the continuous monitoring of intracellular pH while proton excretion was measured simultaneously with a pH-stat. Sodium ions inhibited and potassium ions, at low pH,accelerated the amount of measurable acid excreted extracellularly.(2). In the presence of NaCl (0.15-0.30 M), the total amount of carboxylic acids excreted was inhibited by up to 31%. The intracellular level of fructose 1,6-bisphosphate increased by 58% and levels of 3- phosphoglycerate and pyruvate decreased by 46 and 12%, respectively. The intracellular pH decreased in the presence of sodium ions. It is possible that the low intracellular pH inhibits the activity of the glycolytic enzymes involved in the breakdown of fructose 1,6-bisphosphate to 3- phosphogycerate.(3). The cells grows at pH 5.5 excreted more protons and carboxylic acids than the cells grown at pH 7.0 from glucose. The acidic grown cells kept the intracellular pH higher than the neutral grown cells. These findings indicated that the excretion of acid increased when the cells were grown at acidic pH levels.(4). Under strictly anaerobic conditions, 0.025 mM NaF inhibited proton excretion by 50% in cells grown at pH 7.0 when the pH of reaction mixture was 5.0. Such levels of fluoride are about 10 to 20 times lower than that reported previously.(5). The inhibitory effect of chlorhexidine (0.025mM) alone, fluoride (0.05 mM to 0.4 mM) alone andc hlorhexidine-fluoride combination on proton excretion and intracellular pH in glycolyzing streptococcal cells were examined under different pH conditions. The chlorhexidine-fluoride combination had the advantage of anti-acidogenic effects at both acidic as well as neutral pH levels.

(1).研究了钠离子和钾离子对变形链球菌细胞糖酵解细胞内酸产生和酸排泄的影响。 pH 敏感荧光染料双（羧乙基）-羧基荧光素可以连续监测细胞内 pH，同时用 pH 统计器同时测量质子排泄。在低pH值下，钠离子抑制，钾离子加速可测量的酸排出细胞外的量。(2)．在 NaCl (0.15-0.30 M) 存在下，羧酸的排泄总量被抑制高达 31%。细胞内果糖1,6-二磷酸水平增加了58%，3-磷酸甘油酸和丙酮酸水平分别减少了46%和12%。当钠离子存在时，细胞内 pH 值降低。细胞内低 pH 值可能会抑制糖酵解酶的活性，而糖酵解酶参与将果糖 1,6-二磷酸分解为 3-磷酸甘油酸。(3)。在 pH 5.5 下生长的细胞比在 pH 7.0 下生长的细胞从葡萄糖分泌更多的质子和羧酸。酸性生长的细胞保持细胞内pH值高于中性生长的细胞。这些发现表明，当细胞在酸性 pH 水平下生长时，酸的排泄增加。(4)。在严格厌氧条件下，当反应混合物的 pH 值为 5.0 时，0.025 mM NaF 抑制 pH 7.0 下生长的细胞中 50% 的质子排泄。这种氟化物含量比之前报道的低约 10 至 20 倍。(5)。在不同pH条件下，检测了单独的氯己定（0.025mM）、单独的氟化物（0.05mM至0.4mM）以及氯己定-氟化物组合对糖酵解链球菌细胞的质子排泄和细胞内pH的抑制作用。氯己定-氟化物组合在酸性和中性 pH 水平下都具有抗酸作用的优点。