CENTRAL CONTROL BY CIRCUMVENTRICULAR ORGANS OF SALIVARY SECRETION

声称口腔干燥的人数最近增加了。虽然这是由于老年人和压力的增加以及生活方式的改变，但其内在机制尚不清楚。唾液是由血液和分泌很容易受到渗透压和体积的体液和自主神经系统的影响。本研究旨在探讨穹窿下器官（SFO）作为体液平衡和心血管调节的中心，如何参与唾液分泌。大鼠用于体内和体外实验。在体实验中，通过侧脑室注射高渗盐水和蔗糖来测量饮水和腮腺唾液的变化。我们发现高渗盐水对饮水的诱导和唾液分泌的减少作用大于蔗糖。这些结果表明，唾液分泌受渗透压和钠离子的中枢检测的影响。在离体实验中，我们发现SFO内存在钠离子敏感受体，一定浓度的钠离子可激活SFO神经元。此外，我们发现存在的乙酰胆碱毒蕈碱和烟碱受体的SFO和参与体液平衡。

The number of people who claim oral dryness increases recently. Although this is due to the increase of elderly persons and stress and a change of life style, the underlying mechanisms are not well-known. The saliva is made by the blood and the secretion is easily influenced by osmolarity and volume of body fluid and by the autonomic nervous system. This study was designed to investigate how the subfornical organ (SFO), which is a center of body fluid balance and cardiovascular regulation, is involved in salivary secretion. Rats were used for in vivo and in vitro experiments. In the in vivo experiments, a change of drinking and parotid saliva was measured by intracerebroventricular injection hypertonic saline and sucrose. We found the induction of drinking and the reduction of salivary secretion were larger by the hypertonic saline than by the sucrose. These results indicate that the salivary secretion is affected by central detection of osmolarity and sodium ions. In vitro experiments, we found the existence of sodium ion sensing receptors in the SFO and the activation of SFO neurons by a certain concentration of sodium ions. Further, we found the existence of acetylcholine muscarinic and nicotinic receptors in the SFO and the involvement of them in the body fluid balance.