Real-time monitoring of cellular signaling in salivary secretion by multiphoton excitation imaging

1.用多光子激发显微镜观察了激动剂诱导的大鼠唾液切片和细胞聚集中的Ca^<2+>信号。将Ca^<2+>图像与常规C^<2+>成像系统（ARGUS HiSCA）的结果进行比较。唾液细胞聚集体加载fura-2，监测荧光变化。低浓度（0.1μM）的肾上腺素（Epi）刺激可引起部分导管细胞凋亡增加，而高浓度（1μM）的肾上腺素对大部分细胞有应答。Ca^<2+>反应在一个导管细胞中开始，随后在邻近细胞中升高[Ca^<2+>]i。我们根据它们对Epi和ATP的[Ca^<2+>]i反应来表征导管细胞。约40%的导管细胞对Epi和ATP有高度反应。另有40%的患者对Epi反应较差，但对ATP反应较高。约2%的细胞仅对ATP有反应，10%的细胞对Epi和ATP均无反应。4 . 1μM Epi刺激可诱导胞内-[Ca^<2+>]i波从管腔区向基底区传播。用双光子激发显微镜观察大鼠腮腺切片对[Ca^<2+>]i的反应。1μEpi刺激可引起所有腺泡细胞[Ca^<2+>]i同时升高，而[Ca^<2+>]i反应的起始时间因管细胞而异。细胞间Cat波传播发生在部分导管细胞中。比较激动剂诱导的[Ca^<2+>]i在大鼠颌下腺泡和导管中的反应。Acini对苯酚和P物质有较高的反应；对Epi反应高，对P物质无反应。

1.The agonist-induced Ca^<2+> signaling in rat salivary slices and cell aggregates was visualized using multiphoton excitation microscopy. The Ca^<2+> images were compared with the results obtained by a conventional C^<2+> imaging system (ARGUS HiSCA).2. Salivary cell aggregates were loaded with fura-2 and the changes in fluorescence were monitored. Stimulation with a low concentration (0.1μM) of epinephrine (Epi) induced an increase in in a part of duct cells, while most of the cells responded to its higher concentration (1μM). The Ca^<2+> response was initiated in a duct cell and followed by a rise in [Ca^<2+>]i in the neighboring cells.3. We characterized the duct cells based on their [Ca^<2+>]i-responses to Epi and ATP. About 40 % of duct cells were highly responsive to Epi and ATP. Another 40 % of them were less responsive to Epi but highly responsive to ATP. About 2 % of the cells responded only to ATP, and 10 % of the cells responded to neither Epi nor ATP.4. Stimulation with 1μM Epi induced an intracellular propagating-[Ca^<2+>]i wave from luminal to basal area of duct cells.5. The [Ca^<2+>]i responses in rat parotid gland slices were monitored by two-photon excitation microscopy. Stimulation with 1μEpi caused simultaneous rises in [Ca^<2+>]i in all acinar cells, while the initiation time of [Ca^<2+>]i responses varied with duct cells. The intercellular Cat wave propagation occurred in some duct cells.6. The agonist induced [Ca^<2+>]i responses were compared in rat submandibular acini and ducts. Acini were highly responsive to carbachol and substance P, while duct; were highly responsive to Epi but did not respond to substance P.