July 1, 1986AJP Renal Physiology
Vasopressin increases cytosolic free calcium concentration in glomerular mesangial cells
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Discussion
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Implication
In vitro study demonstrates arginine vasopressin mobilizes intracellular calcium via V1 receptors in rat mesangial cells, indicating a receptor-mediated signaling mechanism for renal regulation.
Key Points
- To measure baseline cytosolic free calcium concentration and characterize calcium mobilization induced by arginine vasopressin and angiotensin II in glomerular mesangial cells.
- Cultured rat glomerular mesangial cells were loaded with intracellular fluorescent indicators quin 2 or fura-2 to monitor dynamic changes in cytosolic free calcium ([Ca2+]f).
- Cells were stimulated with arginine vasopressin (AVP) or angiotensin II (ANG II) under normal conditions, under extracellular calcium depletion using EGTA, and in the presence of a V1 receptor antagonist or cAMP modulators.
- Basal [Ca2+]f was 102 ± 3 nM (quin 2, n=154) and 82 ± 4 nM (fura-2, n=34); addition of 100 nM AVP caused [Ca2+]f to surge from 74 ± 7 nM to a peak of 578 ± 39 nM (n=17) within 10 seconds before declining to 125 ± 9 nM at 115 seconds.
- The [Ca2+]f elevation originated primarily from intracellular calcium stores and was completely inhibited by the V1 receptor antagonist (CH2)5Tyr(Me)VDAVP, but was unaffected by adenylate cyclase activation via isoproterenol or dibutyryl cAMP.
Cite This Study
Bonventre et al. (1986) studied this question.