Singh N
Department of Biochemistry, AIIMS, New Delhi, India.
Int J Exp Pathol. 1990 Dec;71(6):809-14.
The present work was undertaken with the basic objective to compare the effect of related tumour promoters phorbol-12-myristate-13-acetate (PMA), benzoyl peroxide (BP) and mezerein (M) on poly ADP-ribosylation in HeP2 cells. PMA, BP and mezerein showed an increase in the enzyme activity to the extent of 66, 89 and 35% respectively. This was accompanied by a drop in NAD levels of 22% with PMA, 24% with BP and 49% with mezerein, PMA-treated cells showed a decrease in the enzyme activity of 42% with superoxide dismutase (SOD) and catalase (CAT), 18% with butylated hydroxy toluene (BHT), 52% with indomethacin and 32% with 3-aminobenzamine (3AB). However, for BP the inhibition was 16% with CAT, 41% with SOD, 18% with BHT, 34% with 3AB and there was no inhibition with indomethacin. The involvement of active oxygen species was supported by a 2.5-fold increase in superoxide anion levels with PMA and BP and no change with mezerein. There was a twofold and a 2.5-fold increase in Ca2+ influx after PMA and BP treatment respectively. It is concluded that PMA and BP mediate their effect on poly ADP-ribosylation through active oxygen species which in turn stimulates the influx of Ca2+ into cells and this may play an important role in signal transduction.
本研究的基本目的是比较相关肿瘤启动子佛波醇-12-肉豆蔻酸酯-13-乙酸酯（PMA）、过氧化苯甲酰（BP）和芫菁素（M）对HeP2细胞中多聚ADP-核糖基化的影响。PMA、BP和芫菁素使酶活性分别增加了66%、89%和35%。这伴随着PMA使NAD水平下降22%，BP使NAD水平下降24%，芫菁素使NAD水平下降49%。用超氧化物歧化酶（SOD）和过氧化氢酶（CAT）处理PMA处理的细胞后，酶活性下降42%，用丁基羟基甲苯（BHT）处理后下降18%，用吲哚美辛处理后下降52%，用3-氨基苯甲胺（3AB）处理后下降32%。然而，对于BP，CAT的抑制率为16%，SOD的抑制率为41%，BHT的抑制率为18%，3AB的抑制率为34%，吲哚美辛无抑制作用。PMA和BP使超氧阴离子水平增加2.5倍，芫菁素处理后超氧阴离子水平无变化，这支持了活性氧物种的参与。PMA和BP处理后，Ca2+内流分别增加了两倍和2.5倍。结论是，PMA和BP通过活性氧物种介导其对多聚ADP-核糖基化的影响，活性氧物种进而刺激Ca2+流入细胞，这可能在信号转导中起重要作用。
