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. 1995 May;115(1):11–14. doi: 10.1111/j.1476-5381.1995.tb16312.x

Calcium homeostasis in mouse fibroblast cells: affected by U-73122, a putative phospholipase C beta blocker, via multiple mechanisms.

J P Grierson 1, J Meldolesi 1
PMCID: PMC1908738  PMID: 7647965

Abstract

1. The inhibitory effects of the putative phospholipase C beta inhibitor, U-73122, on ligand-induced and thapsigargin-induced [Ca2+]i transients were investigated in mouse fibroblast cells (the L line). 2. Ca2+ release from intracellular stores was stimulated either by ATP (and also by UTP or ADP) working through the activation of a P2U receptor, or by lysophosphatidic acid, which elicited a more pronounced response. 3. U-73122 inhibited the Ca2+ mobilization produced by all the agonists in a dose-dependent manner, consistent with a mode of action involving phospholipase C inhibition. 4. In addition, however, U-73122 slowed the kinetics of intracellular Ca2+ release induced by the Ca(2+)-ATPase inhibitor, thapsigargin, and reduced the influx of Ca2+ across the plasma membrane, following stimulation of store-dependent influx by the latter. 5. We conclude that U-73122 has multiple sites of action, all of which can lead to a change in Ca2+ homeostasis. Thus, particular caution is recommended when employing this agent and when interpreting the results obtained.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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