THE EFFECT OF 2-AMINOETHOXYDIPHENYL BORATE ON STORE-DEPENDENT Ca<sup>2+</sup> ENTRY IN PERITONEAL MACROPHAGES
Store-dependent Ca2+-entry is a universal mechanism of regulated Ca2+ entry in eucariotic cells. To elucidate the pharmacological characteristics of store-dependent Ca2+ entry in macrophages, the effect of 2-aminoethoxydiphenyl borate (2-APB) on store-dependent Ca2+ entry, induced by endoplasmic Ca2+-ATPases inhibitors thapsigargin and cyclopiazonic acid as well as disulfide-containing immunomodulators glutoxim and molixan, was investigated in rat peritoneal macrophages. Using Fura-2AM microfluorimetry we have shown that in rat peritoneal macrophages, as well as in other cell types, 2-APB modulates store-dependent Ca2+ entry in a dose-dependent manner. At concentration of 25 μM 2-APB potentiates Ca2+ entry, while at concentrations of 50 and 100 μM it effectively inhibits store-dependent Ca2+ entry in macrophages. The results additionally confirm that Ca2+ entry induced by glutoxim or molixan occurs via store-dependent mechanism.