Shaposhnikova V V, Egorova M V, Levitman M Kh, Kudriavtsev A A, Sukharev V I, Korystov Iu K
Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Russia.
Izv Akad Nauk Ser Biol. 1998 Mar-Apr(2):225-9.
The effects of mellitin, a component of bee venom activating phospholipase A2, on proliferation and death of the rat thymocytes were studied in a wide concentration range. Cell proliferation was estimated by the accumulation of colchicine metaphases, Necrosis was estimated by cell lysis and Trypan blue staining. Apoptosis was estimated by the type of DNA fragmentation, amount of fragmented DNA, and percentage of cells with hypodiploid DNA set. Low concentrations of mellitin (below 5 micrograms/ml) stimulated proliferation. At higher mellitin concentrations, the thymocytes die by the primary necrosis type. Mellitin did not induce apoptosis in the thymocytes within the concentration range used: on the contrary, at high concentrations, it inhibited apoptosis of the thymocytes in the control and after irradiation. Actinomycin D, inhibitor of RNA synthesis, exerted no effect on the thymocyte death in the presence of mellitin. It has been concluded that activation of phospholipase A2 may induce necrosis, rather than apoptosis, and consequently, activation of phospholipase A2 is not a necessary step in the signalling cascade that initiated apoptosis in the thymocytes.
研究了蜂毒中激活磷脂酶A2的成分蜂毒肽在较宽浓度范围内对大鼠胸腺细胞增殖和死亡的影响。通过秋水仙碱中期相的积累评估细胞增殖，通过细胞裂解和台盼蓝染色评估坏死。通过DNA片段化类型、片段化DNA量以及亚二倍体DNA含量的细胞百分比评估凋亡。低浓度的蜂毒肽（低于5微克/毫升）刺激增殖。在较高的蜂毒肽浓度下，胸腺细胞以原发性坏死类型死亡。在所使用的浓度范围内，蜂毒肽未诱导胸腺细胞凋亡：相反，在高浓度下，它抑制了对照组和照射后胸腺细胞的凋亡。RNA合成抑制剂放线菌素D在存在蜂毒肽的情况下对胸腺细胞死亡没有影响。得出的结论是，磷脂酶A2的激活可能诱导坏死而非凋亡，因此，磷脂酶A2的激活不是启动胸腺细胞凋亡的信号级联反应中的必要步骤。
