Regulation of salivary fluid secretion by calcium ions and cyclic AMP

我们研究了钙离子和环腺苷酸（cAMP）对唾液腺分泌的调节机制。1）卡巴胆碱（CCh）和去甲肾上腺素诱导的α-肾上腺素能作用，从分离的腺泡细胞分泌聚阴离子荧光染料钙黄绿素。(2)异丙肾上腺素（ISP）通过β-作用增强CCh诱导的钙黄绿素释放。(3)CCh和α-肾上腺素能激动剂增加细胞内钙离子浓度。(4)β-肾上腺素能受体激动剂可诱导离体腺泡细胞分泌淀粉酶，但不诱导CCh和α-肾上腺素能受体激动剂。(5)灌流下颌下腺的液体分泌是由CCh和α-肾上腺素能受体激动剂引起的，而不是由β-肾上腺素能受体激动剂。钙黄绿素分泌到唾液中是短暂的诱导CCh和α-肾上腺素能激动剂。(6)钙离子载体A23187逐渐增加液体分泌和瞬时钙黄绿素释放。去除外部钙离子抑制晚期液体分泌，但不钙黄绿素释放。环磷酸腺苷的加入迅速抑制晚期液体分泌。(7)钾通道阻断剂Ba ~（2+）抑制液体分泌和钙黄绿素释放。Cl-通道阻断剂DPC不抑制钙黄绿素的释放，但抑制晚期液体分泌。(8)CCh的加入迅速增加了管腔空间和钙黄绿素分泌到细胞内的空间，然后诱导基底侧膜下的空泡。去除外源钙离子、Ba ~（2+）和DPC可抑制CCh诱导的空泡形成。（8）CCh和ISP刺激后，多种蛋白质酪氨酸残基磷酸化。

We have investigated regulation mechanism of fluid secretion from the salivary glands by calcium ions and cyclic AMP.1) Carbachol (CCh) and alpha-adrenergic action of noradrenaline induced secretion of polyanionic fluorescent dye, calcein, from isolated acinar cells. (2) Isoproterenorol (ISP) potentiated the CCh-induced release of calcein through beta-action. (3) CCh and alpha-adrenergic agonists increased the intracellular concentration of calcium ions. (4) Amylase secretion from isolated acinar cells was induced by beta-adrenergic agonists, but not CCh and alpha-adrenergic agonists. (5) The fluid secretion from perfused submandibular glands was induced by CCh and alpha-adrenergic agonists, but not by beta-adrenergic agonists. The secretion of calcein into the saliva was transiently induced by CCh and alpha-adrenergic agonists. (6) Calcium ionophore A23187 gradually increased the fluid secretion and transient calcein release. Removal of externalcalcium ions suppressed the late fluid secretion, but not calcein release. Addition of cyclic AMP rapidly suppressed the late fluid secretion. (7) K-Channel blocker Ba2+ inhibited the fluid secretion and calcein release. Cl-channel blocker DPC did not inhibit the calcein release, but suppressed the late fluid secretion. (8) Addition of CCh rapidly increased the luminal space and the secretion of calcein into intracellular apaces, and then induced vacuoles beneath the basolateral membranes. Removal of external calcium ions, Ba2+ and DPC suppressed the CCh-induced formation of vacuoles. (8)The phosphorylation of tyrosine-residues was observed in various proteins after CCh and ISP stimulation.