Whitford G M
Department of Oral Biology, Medical College of Georgia, Augusta 30912-1129.
Calcif Tissue Int. 1994 May;54(5):421-5. doi: 10.1007/BF00305530.
This 30-day balance study with weanling rats was designed to determine the effects of plasma fluoride and dietary calcium concentration and their interaction on the absorption, balance, and tissue concentrations of fluoride. The three major groups differed according to the total exposure and plasma concentrations of fluoride. One group received fluoride only in the diet and the other two received additional fluoride by continuous infusion from miniosmotic pumps implanted S.C. Each group was divided into two subgroups with dietary calcium concentrations of 0.4% or 1.4%. Fluoride intake with the diet did not differ among the groups. Fecal fluoride excretion was directly related to plasma fluoride concentration. The absorption and balance of dietary fluoride were inversely related to plasma fluoride concentration. These effects were greatest in the groups fed the 1.4% calcium diet. The interactions of plasma fluoride and dietary calcium on these variables were highly significant (P < 0.0001). The balance of dietary fluoride was negative in the four groups that received additional fluoride by infusion. In the two groups that received fluoride only in the diet, the plasma and bone fluoride concentrations were 41% and 59% lower, respectively, in the 1.4% dietary calcium group. The findings indicate that net fluoride secretion into the GI tract can occur when plasma fluoride concentrations and calcium intake are elevated. They suggest that elevated plasma fluoride levels and calcium intake are factors that may diminish the effect of oral fluoride treatment in osteoporotic patients.
这项针对断奶大鼠的为期30天的平衡研究旨在确定血浆氟化物、膳食钙浓度及其相互作用对氟化物吸收、平衡和组织浓度的影响。三大组根据氟化物的总暴露量和血浆浓度而有所不同。一组仅在饮食中摄入氟化物，另外两组通过植入皮下的微型渗透泵持续输注额外的氟化物。每组再分为两个亚组，膳食钙浓度分别为0.4%或1.4%。各组饮食中的氟化物摄入量没有差异。粪便氟化物排泄与血浆氟化物浓度直接相关。膳食氟化物的吸收和平衡与血浆氟化物浓度呈负相关。在喂食1.4%钙饮食的组中，这些影响最为明显。血浆氟化物和膳食钙对这些变量的相互作用非常显著（P < 0.0001）。通过输注接受额外氟化物的四组中，膳食氟化物的平衡为负。在仅在饮食中摄入氟化物的两组中，1.4%膳食钙组的血浆和骨氟化物浓度分别低41%和59%。研究结果表明，当血浆氟化物浓度和钙摄入量升高时，胃肠道可能会出现氟化物净分泌。研究结果提示，血浆氟化物水平升高和钙摄入量增加可能是削弱骨质疏松症患者口服氟化物治疗效果的因素。
