SALIVARY GLAND SECRETORY MECHANISMS DURING NORMAL AND ALTERED FUNCTIONAL STATES

口腔的健康是靠唾液分泌维持的。 唾液腺的主要功能是产生这些复合体 体液。我们利用唾液腺的体外分散细胞，在 活体空心腺和培养的唾液细胞系作为实验室 了解唾液形成控制机制的模型。我们有 我们的研究主要集中在神经递质对分泌物的调节 事件。在本报告所述期间，信号的主要重点 大鼠腮腺M受体(MAChRs)的研究继续 腺泡细胞。在腮腺细胞中，刺激mAChRs的结果 在肌醇磷酸盐的生成中，通过激活 磷脂酶C。随后，这种反应导致 细胞内钙离子水平和液体分泌。我们一直在继续 大鼠完整腮腺细胞mAChRs的结合特性 一种亚型非选择性拮抗剂(NMS，N-甲基东莨菪碱)。我们有 确定了中等人口(约30%-40%)的备用 三磷酸肌醇的形成受体是存在的。我们有 碘标记外分泌腺中mAChRs的体内持续研究 QNB对映体及药代动力学分析。 这些实验促进了一项临床研究的发展 检测正常人mAChRs的方法。要理解 唾液腺如何运输水分我们已经开始研究一种推定的 水路，CHIP28。我们已经分离到一个编码CHIP28样蛋白的基因 从大鼠腮腺文库中提取蛋白质并检测其细胞 用原位杂交法测定其在腺体中的分布。我们还有 启动将外源基因转移到大鼠唾液腺的努力 利用复制缺陷重组腺病毒(Ad)载体进行体内研究 (例如，含有编码大肠杆菌β-半乳糖苷酶、β-半乳糖苷酶、β-半乳糖苷酶的基因； 和人α1抗胰蛋白酶，α1AT)。逆行两天后 腺泡内导管内可见Ad-β-Gal的显著表达 和所有主要唾液腺的导管细胞。转让 Alpha1AT基因导致腺唾液中这种蛋白质的分泌 4-10天。

The health of the oral cavity is maintained by salivary secretions. The principal function of salivary glands is to produce these complex fluids. We utilize in vitro dispersed cells of salivary glands, in vivo cannulated glands, and cultured salivary cell lines as laboratory models to understand mechanisms controlling saliva formation. We have focused most of our studies on neurotransmitter regulation of secretory events. During this reporting period the primary focus of signaling studies continues to be muscarinic receptors (mAChRs) in rat parotid gland acinar cells. In parotid cells, stimulation of mAChRs results in the generation of inositol phosphates via the activation of phospholipase C. Subsequently this response leads to the elevation of cytosolic Ca2+ levels and fluid secretion. We have continued to characterize mAChRs in intact rat parotid cells using the binding of a subtype non-selective antagonist (NMS, N-methylscopolamine). We have determined that a moderate population (approximately 30-40%) of spare receptors exist for inositol trisphosphate formation. We have continued in vivo studies of mAChRs in exocrine glands using iodinated QNB (quinuclidinyl benzilate) enantiomers and phamacokinetic analyses. These experiments have led to the development of a clinical research protocol to examine mAChRs in normal human volunteers. To understand how salivary glands transport water we have begun studies on a putative water channel, CHIP28. We have isolated a cDNA encoding a CHIP28-like protein from a rat parotid library and examined its cellular distribution in this gland by in situ hybridization. We have also initiated efforts to transfer foreign genes into rat salivary glands in vivo using replication deficient recombinant adenovirus (Ad) vectors (e.g. containing genes encoding E. Coli beta-galactosidase, beta gal; and human alpha 1 antitrypsin, alpha1AT). Two days after retrograde duct instillation of Ad-beta gal striking expression is seen in acinar and ductal cells of all major salivary glands. Transfer of the alpha1AT gene results in secretion of this protein in gland saliva for 4-10 days.