Sakano S, Takemura H, Ohshika H
Department of Pharmacology, School of Medicine, Sapporo Medical University, Japan.
Res Commun Mol Pathol Pharmacol. 1994 Nov;86(2):175-82.
Effects of various receptor agonists on cytoplasmic Ca2+ concentration ([Ca2+]i) were examined in fura-2-loaded Mardin-Darby canine kidney (MDCK) monolayer cells. Carbachol (100 microM) increased [Ca2+]i which slightly declined to a sustained increase in [Ca2+]i. On the other hand, [Ca2+]i elevated by 100 nM bradykinin (BK) declined to a resting level of [Ca2+]i even in the presence of BK. After washout of BK, the subsequent addition of a higher concentration of BK (1 microM) caused a smaller increase in [Ca2+]i than that induced by 100 nM BK. Isoproterenol (100 microM) did not increase [Ca2+]i by itself but caused an transient increase in [Ca2+]i in the presence of 1 mM isobutyl-methylxanthine (IBMX). Prostaglandin E1 (1 microM) resulted in a slight increase in [Ca2+]i which was potentiatedin the presence of 1 mM IBMX. The microsomal Ca(2+)-ATPase inhibitor thapsigargin (100 nM) caused a sustained increase in [Ca2+]i. These results suggest that MDCK cells have multiple Ca2+ signaling pathways which may regulate epithelial cell functions.
在装载了fura-2的马尔丁-达比犬肾（MDCK）单层细胞中，检测了各种受体激动剂对细胞质钙离子浓度（[Ca2+]i）的影响。卡巴胆碱（100微摩尔）使[Ca2+]i升高，随后略有下降，然后持续升高。另一方面，即使存在缓激肽（BK），由100纳摩尔缓激肽升高的[Ca2+]i仍降至[Ca2+]i的静息水平。冲洗掉BK后，随后加入更高浓度的BK（1微摩尔）引起的[Ca2+]i升高幅度小于100纳摩尔BK诱导的升高幅度。异丙肾上腺素（100微摩尔）本身不会增加[Ca2+]i，但在存在1毫摩尔异丁基甲基黄嘌呤（IBMX）的情况下会引起[Ca2+]i短暂升高。前列腺素E1（1微摩尔）导致[Ca2+]i略有升高，在存在1毫摩尔IBMX的情况下会增强。微粒体Ca(2+)-ATP酶抑制剂毒胡萝卜素（100纳摩尔）导致[Ca2+]i持续升高。这些结果表明，MDCK细胞具有多种钙离子信号通路，可能调节上皮细胞功能。
