Komulainen H, Bondy S C
Brain Res. 1987 Jan 13;401(1):50-4. doi: 10.1016/0006-8993(87)91162-0.
The role of polyamines in the regulation of free intrasynaptosomal Ca2+, [Ca2+]i was studied. After preincubation of rat brain synaptosomes with 5 mM difluormethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, the K+-induced increase of [Ca2+]i was 33% less than that in non-treated synaptosomes. Putrescine (1 mM) added together with DFMO negated the effect of DFMO suggesting that abnormally low polyamine concentrations were the reason for the diminished K+-response. Putrescine alone did not alter the K+-response to [Ca2+]i. Instead putrescine (0.5 mM) caused a rapid (less than 10 s) transient increase in [Ca2+]i but did not simultaneously increase 45Ca2+ uptake into polarized synaptosomes. Neither spermidine nor spermine (0.5 mM) significantly altered [Ca2+]i. The results suggest that polyamines play a role in the regulation of free intrasynaptosomal Ca2+.
研究了多胺在调节突触小体内游离钙离子（[Ca2+]i）方面的作用。用5 mM二氟甲基鸟氨酸（DFMO，鸟氨酸脱羧酶的不可逆抑制剂）对大鼠脑突触体进行预孵育后，钾离子诱导的[Ca2+]i增加比未处理的突触体低33%。与DFMO一起添加的腐胺（1 mM）消除了DFMO的作用，表明多胺浓度异常低是钾离子反应减弱的原因。单独的腐胺不会改变对[Ca2+]i的钾离子反应。相反，腐胺（0.5 mM）导致[Ca2+]i迅速（不到10秒）短暂增加，但不会同时增加极化突触体对45Ca2+的摄取。亚精胺和精胺（0.5 mM）均未显著改变[Ca2+]i。结果表明多胺在调节突触小体内游离钙离子方面发挥作用。
