β-淀粉样蛋白对培养神经细胞的毒性作用及神经节苷脂的保护作用

TOXIC EFFECT OF β-AMYLOID PROTEIN ON CULTURED NERVE CELLS AND PROTECTING EFFECT OF GANGLIOSIDES

向培养液中加入15mmol／L的β-AP1-40，48h后，发现原代培养的海马细胞内Ca2+的浓度明显增高，对照组为23．9±3．6（n=51）而β-AP组为36．5±15．8（n=30），两组比较P＜0．001，有非常显著性的差别。对照组的乳酸脱氢酶没有明显变化，而β－AP组在加β－AP1－4048h后乳酸脱氢酶明显增加，从52iu／L增加到105iu／L，实增加了101％。实验结果表明，β－AP1-40对培养的神经细胞有明显的毒性作用，但没有发现形态学的变化和对细胞的特异性。如在培养液中加β－AP1-40的同时再加25mg／ml的神经节苷脂（GAs）可明显减弱β-AP1-40引发的胞内Ca2+浓度和培养液中LDH浓度的升高。β-AP＋GAs组胞内Ca2+浓度为27.7±5.58，与β-AP组比较，有显著性差异（P＜0．01）。β-AP组海马细胞培养液中乳酸脱氢酶的浓度增高为101％，而β-AP-GAs组培养液中乳酸脱氢酶的浓度增高仅为67％。在NG108－15细胞上也获得了相同的结果。单唾液酸神经节苷脂虽有与GAs类似的作用，但较弱。这些实验结果指出，神经节苷脂和单唾液酸神经节苷脂均能拮抗β-AP1-40的毒性作用，从而对细胞可起到保护作用。

Primary cultured hippocampal cells and NG108-15 cells were used in experiments. Forty eight hours after adding 15 μmol/L β-AP1-40 to culture medium, the intracellular Ca2+ concentration increased significantly. The Ca2+ concentrations of cultured hippocampal cells in control group and β-AP group were 23. 9±3. 6 (n= 51 ) and 36. 5±15. 8 (n=30) respectively (P<0.001). The level of LDH concentration in culture medium was obviously raised at 101% by administration of β-AP. Although no morphological change was found. The similar result was obtained from NG108-15 cells. Moreover, high concentration of intracellular Ca2+ and LDH culture medium were decreased by gangliosides (GAs) or GM1 (25 mg/ml). The Ca2+ concentration of βAP treated group of hippocampal cells was 36. 5 ± 15. 8, but that of β-AP+GAs group was 27. 7 ± 5. 58 (P<0. 01 ). The increased LDH concentration in culture medium of β-AP group was decreased by GAs from 101 % to 67 %. GM1 has the same effcet that seems a little weaker than the effect of GAs. These results show that gangliosides have certain protecting effect on cultured nerve cells from toxicity of β-AP.