EFFECTS OF LEAD ON SALIVARY GLANDS AND DENTAL CARIES

高血铅是儿童最常见的疾病之一。 和对儿童健康最普遍的环境威胁 美国“(Healthy People 2000，p.319)。铅罐的毒性。 几乎在每个器官系统都有表现。铅和其他重金属 干扰正常的钙代谢。钙代谢的紊乱有 严重后果会影响唾液腺功能、釉质形成。和 牙本质形成。铅一旦进入细胞，其毒性作用是最大的 可能是通过激活蛋白激酶C和/或钙调素- 通过修饰反应性巯基或通过修饰依赖的蛋白激酶 结合到离子转运体上的钙结合部位。唾液腺 功能减退显然与龋齿增加有关。铅可能会影响 直接通过竞争钙结合位点致龋病，从而 影响牙釉质脱矿和再矿化。唾液中的铅 而菌斑可能会导致氟化铅的形成 本质上是不溶的，导致氟化物不能用于龋齿 起到了保护作用。我们建议确定产前的影响 铅暴露对龋齿易感性的影响 铅对唾液腺发育和功能的影响 诱导流量和精选的有机和无机成分。钙 将监测铅和重金属暴露后的新陈代谢 通过观察刺激诱导的[Ca~(2+)]i动员的步骤 唾液腺泡细胞测量：L)磷酸肌醇形成，2) 细胞内钙释放；3)二价阳离子内流。可能的 铅和重金属对钙调节离子转运的影响 与体液分泌有关的机制将通过分析确定 细胞内pH[Cl-]和[Na]。从这些研究中获得的知识 可能会产生重大的社会影响，增强我们对 龋病的病因和发病机制，以及铅和铅的影响 重金属对唾液腺生理的影响。

High blood lead levels are among the most prevalent childhood conditions and the most prevalent environmental threat to the health of children in the United States" (HEALTHY PEOPLE 2000, p. 319). Toxicity from lead can be manifested in virtually every organ system. Lead and other heavy metals interfere with normal Ca2+ metabolism. Perturbation of Ca2+ metabolism has severe consequences on salivary gland function, amelogenesis. and dentinogenesis. Once lead enters the cell, its toxic effects are most likely mediated by activating protein kinase C and/or Ca2+ calmodulin- dependent protein kinase by modifying reactive sulfhydryl groups or by binding to Ca2+ binding sites on ion transporters. Salivary gland hypofunction is clearly related to increased caries. Lead may affect cariogenesis directly by competing for calcium binding sites, thereby affecting demineralization and remineralization of enamel. Lead in saliva and plaque may result in the formation of lead fluoride which is essentially insoluble, rendering fluoride unavailable for its caries protective effect. We propose determining the influence of prenatal exposure to lead on susceptibility to dental caries and also explore the effect of lead on salivary gland development and function as determined by induced flow rate and selected organic and inorganic constituents. Calcium metabolism subsequent to lead and heavy metal exposure will be monitored by observing steps involved in stimulation-induced [Ca2+) mobilization in salivary acinar cells by measuring: l) inositol phosphate formation, 2) intracellular Ca2+ release, and 3) divalent cation influx. Possible influence of lead and heavy metals on Ca2+-regulated ion transport mechanisms associated with fluid secretion will be determined by assaying intracellular pH [Cl-] and [Na+]. Knowledge gained from these studies could have a major societal impact, enhance our understanding of the etiology and pathogenesis of dental caries, and the effects of lead and heavy metals on salivary gland physiology.