Burnatowska-Hledin M A, Spielman W S
Am J Physiol. 1987 Aug;253(2 Pt 2):F328-32. doi: 10.1152/ajprenal.1987.253.2.F328.
We examined the effects of arginine vasopressin (AVP), parathyroid hormone (PTH), and bradykinin (BK) on the cytosolic free calcium concentration ([Ca]i) in cultured LLC-PK1 and MDCK kidney cell lines by use of the fluorescent Ca chelator fura-2. In LLC-PK1 cells, the addition of AVP but not [1-desamino-8-D-arginine]vasopressin (dDAVP, V2 agonist), PTH, or BK (10(-6) M) caused a significant increase in [Ca]i. The AVP-induced increase in [Ca]i from 61 +/- 6 to 225 +/- 44 nM (n = 7, P less than 0.01) was rapid and transient, returning to base line in 2 to 3 min. The effect of AVP was dose dependent and was present at 1 (61% increase) but not 5 min after extracellular Ca was removed. The effect of 10(-6) M AVP could be blocked with the pressor (V1) antagonist, d(CH2)5Tyr(Me)AVP, but not dDAVP. In MDCK cells, BK, but not AVP and PTH, increased [Ca]i from 146 +/- 11 to 281 +/- 31 nM (n = 9, P less than 0.001). The removal of extracellular Ca (5 min), reduced but did not abolish this effect. These results indicate that [Ca]i mobilized by activation of V1-receptors may mediate AVP-regulated function in some transporting epithelia.
我们使用荧光钙螯合剂fura-2，研究了精氨酸加压素（AVP）、甲状旁腺激素（PTH）和缓激肽（BK）对培养的LLC-PK1和MDCK肾细胞系胞质游离钙浓度（[Ca]i）的影响。在LLC-PK1细胞中，添加AVP而非[1-去氨基-8-D-精氨酸]加压素（dDAVP，V2激动剂）、PTH或BK（10⁻⁶ M）会导致[Ca]i显著升高。AVP诱导的[Ca]i从61±6 nM升高至225±44 nM（n = 7，P<0.01）迅速且短暂，在2至3分钟内恢复至基线水平。AVP的作用呈剂量依赖性，在去除细胞外钙后1分钟（升高61%）时存在，但5分钟时不存在。10⁻⁶ M AVP的作用可被升压（V1）拮抗剂d(CH2)5Tyr(Me)AVP阻断，但不能被dDAVP阻断。在MDCK细胞中，BK而非AVP和PTH使[Ca]i从146±11 nM升高至281±31 nM（n = 9，P<0.001）。去除细胞外钙（5分钟）可减弱但并未消除这种作用。这些结果表明，通过V1受体激活而动员的[Ca]i可能在某些转运上皮细胞中介导AVP调节的功能。
