Gonçalves M L, Pinto F, Ribeiro J A
Laboratory of Pharmacology, Gulbenkian Institute of Science, Oeiras, Portugal.
J Neurochem. 1991 May;56(5):1769-73. doi: 10.1111/j.1471-4159.1991.tb02079.x.
The effect of adenosine on 45Ca2+ uptake by rat brain synaptosomes stimulated by electrical pulses was investigated. 45Ca2+ uptake was voltage dependent. Adenosine (1 nM-1 microM) decreased the uptake of 45Ca2+ induced by electrical stimulation (amplitude, 20 V; duration, 400 microseconds; frequency, 10 pulses/s) in a concentration-dependent manner. At a concentration of 1 microM, adenosine almost abolished the 45Ca2+ uptake induced by electrical stimulation (92.9 +/- 5.3% inhibition), but when the calcium uptake was induced by high-K+ (60 mM) medium, the effect of adenosine (1 microM) was smaller (43.8 +/- 5.2% inhibition). The inhibitory effect of 1 microM adenosine on calcium uptake induced by electrical stimulation was antagonized by 1,3-dipropyl-8-p-sulfophenylxanthine (5 microM). The possibility that adenosine interacts with the calcium channels opened by electrical stimulation is discussed.
研究了腺苷对电脉冲刺激的大鼠脑突触体摄取45Ca2+的影响。45Ca2+摄取是电压依赖性的。腺苷（1 nM - 1 microM）以浓度依赖性方式降低电刺激（幅度20 V；持续时间400微秒；频率10脉冲/秒）诱导的45Ca2+摄取。在1 microM浓度下，腺苷几乎完全消除电刺激诱导的45Ca2+摄取（抑制率92.9 +/- 5.3%），但当钙摄取由高钾（60 mM）培养基诱导时，腺苷（1 microM）的作用较小（抑制率43.8 +/- 5.2%）。1 microM腺苷对电刺激诱导的钙摄取的抑制作用被1,3 - 二丙基 - 8 - 对磺基苯基黄嘌呤（5 microM）拮抗。讨论了腺苷与电刺激打开的钙通道相互作用的可能性。
