柞蚕杀菌肽D对人直肠癌细胞的杀伤作用及机制

柞蚕杀菌肽D在0．05～200μg／mL浓度范围内对直肠癌细胞的生长有明显抑制作用；用氚标记的胸腺嘧啶核苷（3H-TdR）对癌细胞的掺入试验，发现能抑制细胞DNA的合成．导致3H-TdR掺入率明显下降。钙离子螯合剂Indo-1-AM能与癌细胞内钙离子螯合而产生特异性荧光，通过粘附细胞激光定量分析及筛选议的观察，发现杀菌肽能破坏细胞的钙离子通道，钙离子迅速逸出细胞外。采用电子显微镜观察直肠癌细胞超微结构的变化，发现杀菌肽首光破坏细胞膜致微绒毛收缩、融合，继而导致细胞器的破坏，最终细胞崩解死亡。正常猴肾细胞CV1，在1.00μg／mL浓度杀菌肽D作用48h，尚未发现不良影响。

CYTOCIDAL EFFECTS OF CECROPIN D FROM CHINESE OAK SILKWORM ON HUMAN ADENOCARCINOMA OF RECTUM

0. 05~2. 0 μg/ml of cecropin D from chinese oak silkworm (Antheraea pernyi) wasfound effective in inhibition of the growth of adenocarcinoma cells. Further studiesdemonstrated that cecropin D inhibited the permeation of 3H-labelled thymine deoxyribonucleoside (3H-TdR) into the cells thus the DNA synthesis. It also destroyed the calcium ion channel,resulted in quick release of calcium ions out of the cells. Observationunder electron microscope showed that cecropin D first damaged the cell membrane,thencaused shrinkage and fusion of microvilli,destroyed the cell organelles and finally thecells died and collapsed. But the damage could not be observed to normal mammal kidenycell line from monkey.