SALIVARY GLAND SECRETORY MECHANISMS DURING NORMAL AND ALTERED FUNCTIONAL STATES

口腔的健康是靠唾液分泌维持的。媒体 辅助体 唾液腺的功能就是产生这些复杂的液体。我们利用 N体外 分散的唾液腺细胞以了解控制唾液流失的机制 一个队形。 我们的研究重点是分泌性前夕的神经递质调节。 S和 相关的信令机制。在本报告所述期间，主要 研究的重点 大鼠腮腺腺泡内M受体的表达 LS和他们的 通过特定的G蛋白与功能反应相偶联。我们也有INI 专门化研究 这些细胞中的α-肾上腺素能受体(α1-ARs)。在腮腺细胞中 刺激 MAChRs的活性导致肌醇磷酸盐的生成 一种 磷脂酰肌醇4，5-二磷酸特异性磷脂酶C 这 反应导致细胞内钙离子水平和液体分泌增加 此外，mAChRs还可介导激动剂诱导的cAMP抑制 提顿。我们 已经表征了一种亚型非选择性拮抗剂(QUU)的结合 乙二酰亚胺 对完整的大鼠腮腺细胞的mAChRs。特定的绑定是 可满足的， 依赖时间和温度(Bmax约为80fmol/mg蛋白质；Kd 最接近 晚上10点)。此外，我们还评估了mAChR占有率与 第二 信使编队，确定适度的人口(大约 -40%) 三磷酸肌醇(IP3)的形成存在备用受体。我们占上风 狡猾的报道 大鼠腮腺M3-mAChRs与两种不同信号转导G蛋白偶联 移民局。这 年，我们测定了编码该基因区域的核苷酸序列 或基因 参与G蛋白偶联，我们观察到它实际上是相同的 给其他人 报道了3个序列。因此，mAChR本身不太可能负责 对于 发散耦合。此外，我们已经证明了α1-肾上腺素能 感受器 参与液体分泌反应的亚型是α1a。

The health of the oral cavity is maintained by salivary secretions. The pr cipal function of salivary glands is to produce these complex fluids. We utilize n vitro dispersed cells of salivary glands to understand mechanisms controlling sal a formation. We have focused our studies on neurotransmitter regulation of secretory eve s and associated signalling mechanisms. During this reporting period the primary ocus of study continues to be muscarinic receptors (mAChRs) in rat parotid gland acinar c ls and their coupling to functional responses via specific G proteins. We have also ini ated studies of alpha-adrenergic receptors (alpha1-ARs) in these cells. In parotid cell stimulation of mAChRs results in the generation of inositol phosphates via the activati of a phosphatidylinositol 4,5-bisphosphate specific phospholipase C. Subsequent this response leads to the elevation of cytosolic Ca2+ levels and fluid secretio Additionally, mAChRs can mediate the inhibition of agonist induced cAMP for tion. We have characterized the binding of a subtype non-selective antagonist (quinu idinyl benzilate, QNB) to mAChRs in intact rat parotid cells. Specific binding is aturable, time- and temperature-dependent (Bmax approximately 80 fmol/mg protein; Kd proximately 100 pM). Also, we have assessed the relationship between mAChR occupancy a second messenger formation, determining that a moderate population (approximately -40%) of spare receptors exist for inositol trisphosphate (IP3) formation. We previ sly reported that rat parotid M3-mAChRs couple to two different signal transducing G pro ins. This year we determined the nucleotide sequence encoding the region of this rece or gene involved in G-protein coupling and we observed that it is virtually identic to other reported 3 sequences. Thus, the mAChR itself is unlikely to be responsibl for the divergent coupling. Additionally, we have shown that the alpha1-adrenergic eceptor subtype involved in the fluid secretory response is alpha1A.