Springer Online Journal Archives 1860-2000
Abstract Effects of different forms of C2-5A (2′,5′ApApA; 2′,5′ApApepoxyA; and 3′,5′ApApA) on high voltage-activated (HVA) calcium currents in GH3 cells were studied using the whole-cell patch-clamp recording technique. Addition of 10 µM 2′,5′ApApA, a “core” (dephosphorylated) oligoadenylate, to the pipette solution induced an increase in HVA calcium current. Ten minutes after the whole-cell configuration was established, the current magnitude was enhanced about twofold compared with that observed at 2 min. High concentration of Mg2+ (5 µM) in the pipette solution blocked this effect. 2′,5′ApA and 3′,5′ApApA oligoadenylates, and products of 2′,5′A hydrolysis, adenosine and AMP, did not change the value of HVA current. A chemically modified analog of 2′,5′ApApA (2′,5′ApApepoxyA) has been the oligoadenylate most stable under phosphodiesterase action. Addition of 2′,5′ApApepoxyA to the pipette solution under the same conditions caused a smaller effect than 2′,5′ApApA did.
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