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）对唾液腺分泌液的调节机制，以及去甲肾上腺素诱导腺泡细胞分泌多阴离子荧光染料钙黄蛋白的α -肾上腺素能作用。(2)异丙孕激素（Isoproterenorol， ISP）通过β -作用增强cch诱导的钙黄蛋白释放。(3) CCh和α -肾上腺素能激动剂增加细胞内钙离子浓度。(4) β -肾上腺素能激动剂能诱导分离的腺泡细胞分泌淀粉酶，而CCh和α -肾上腺素能激动剂则不能。(5) CCh和α -肾上腺素能激动剂可诱导颌下腺液体分泌，而β -肾上腺素能激动剂不能诱导。CCh和α -肾上腺素能激动剂可瞬间诱导钙黄蛋白分泌到唾液中。(6)钙离子载体A23187逐渐增加体液分泌和钙黄蛋白的短暂释放。去除外源性钙离子抑制晚期体液分泌，但不抑制钙黄蛋白释放。添加环状AMP可迅速抑制晚期液体分泌。(7) k通道阻滞剂Ba2+抑制体液分泌和钙黄素释放。cl通道阻滞剂DPC对钙黄素释放无抑制作用，但对后期液体分泌有抑制作用。(8) CCh的加入使细胞腔隙迅速增大，钙黄蛋白分泌到细胞内腔隙，并在基底膜下形成空泡。去除外部钙离子、Ba2+和DPC可抑制cch诱导的液泡形成。(8)在CCh和ISP刺激下，多种蛋白的酪氨酸残基发生磷酸化。

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.