Regulation of salivary fluid secretion by calcium ions and cyclic AMP

我们研究了钙离子和环磷酸腺苷(CCH)对唾液腺分泌液体的调节机制，以及去甲肾上腺素诱导分离的腺泡细胞分泌多阴离子荧光染料钙黄绿素的α-肾上腺素能作用。(2)异丙肾上腺素可通过β作用增强CCH诱导的钙黄素释放。(3)CCH和α-肾上腺素能激动剂可增加细胞内钙离子浓度。(4)β-肾上腺素能激动剂能诱导腺泡细胞分泌淀粉酶，而CCH和α-肾上腺素能激动剂不能诱导腺泡细胞分泌淀粉酶。(5)CCH和α-肾上腺素能激动剂能诱导颌下腺分泌液体，而β-肾上腺素能激动剂不能诱导颌下腺分泌液体。CCH和α-肾上腺素能激动剂可短暂诱导钙黄绿素分泌到唾液中。(6)钙离子载体A23187逐渐增加液体分泌和瞬时钙黄绿素释放。去除外源性钙离子可抑制晚期液体分泌，但不影响钙黄素的释放。加入环状AMP可迅速抑制晚期液体分泌。(7)钾通道阻断剂Ba2抑制液体分泌和钙黄绿素释放。CL通道阻滞剂DPC不能抑制钙黄素的释放，但能抑制晚期液体的分泌。(8)加入CCH后，管腔间隙迅速增大，细胞内钙黄绿素分泌增加，基底膜下形成空泡。去除外源钙离子、Ba2和DPC可抑制CCH诱导的空泡形成。(8)CCH和ISP刺激后，不同蛋白质中均有酪氨酸残基的磷酸化。

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.