Extracellular-Added ADP-Ribose Increases Intracellular Free Ca2+ Concentration Through Ca2+ Release From Stores, but Not Through TRPM2-Mediated Ca2+ Entry, in Rat β-Cell Line RIN-5F

• Main Authors: Ishii Masakazu (Author), Shimizu Shunichi (Author), Hagiwara Tamio (Author), Wajima Teruaki (Author), Miyazaki Akira (Author), Mori Yasuo (Author), Kiuchi Yuji (Author)
• Format: Book
• Published: Elsevier, 2006-01-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Abstract.: Intracellular ADP-ribose is an activator of TRPM2, which is a Ca2+-permeable channel and mediates H2O2-induced cell death, in the TRPM2-expressing rat β-cell line RIN-5F. We examined the effect of extracellular-added ADP-ribose on intracellular Ca2+ concentration in RIN-5F cells. ADP-ribose induced Ca2+ release from the thapsigargin-sensitive Ca2+ store, but not Ca2+ entry across the plasma membrane. A phospholipase C (PLC) inhibitor and a non-specific IP3 receptor inhibitor blocked its Ca2+ release. H2O2-induced Ca2+ entry through TRPM2 was not affected by extracellular ADP-ribose. These findings suggest that extracellular-added ADP-ribose induces Ca2+ release through the PLC-IP3 pathway and does not act as a TRPM2 activator. Keywords:: ADP-ribose, hydrogen peroxide, TRPM2

Item Description

1347-8613
10.1254/jphs.SCJ06001X