SALIVARY GLAND SECRETORY MECHANISMS DURING NORMAL AND ALTERED FUNCTIONAL STATES

口腔的健康是由唾液分泌物维持的。 唾液腺的主要功能是产生这些复合物 流体. 我们利用体外分散的唾液腺细胞， 体内插管腺体，培养的唾液细胞系作为实验室 了解控制唾液形成的机制。 我们有 我们的研究主要集中在神经递质对分泌性 事件 在本报告所述期间， 研究继续是大鼠腮腺中的毒蕈碱受体（mAChR） 腺泡细胞 在腮腺细胞中，mAChRs的刺激导致 在通过活化肌醇磷酸产生肌醇磷酸中， 脂酶C已 随后，这种反应导致 细胞质Ca 2+水平和液体分泌。 我们继续 使用以下结合来表征完整大鼠腮腺细胞中的mAChR： 一种亚型非选择性拮抗剂（NMS，N-甲基东莨菪碱）。 我们有 确定中等数量（约30-40%）的备用 存在用于三磷酸肌醇形成的受体。 我们有 使用碘标记的外分泌腺中的mAChR的持续体内研究 QNB（奎宁环基二苯甲酸酯）对映体和药代动力学分析。 这些实验导致了临床研究的发展 在正常人类志愿者中检查mAChR的方案。 了解 唾液腺是如何运输水分的我们已经开始研究 水通道，CHIP 28。 我们已经分离了一个编码CHIP 28样蛋白的cDNA， 从大鼠腮腺文库中提取蛋白质，并检测其细胞 分布在这个腺体通过原位杂交。 我们还 开始尝试将外源基因转移到大鼠唾液腺中， 体内使用复制缺陷型重组腺病毒（Ad）载体 (e.g.含有编码E.大肠杆菌β-半乳糖苷酶; 和人α 1抗胰蛋白酶，α 1AT）。 逆行后两天 腺泡内滴注Ad-beta gal显著表达 以及所有主要唾液腺的导管细胞。 转移 alpha 1AT基因导致这种蛋白质在腺唾液中分泌， 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.