Berta P, Phaneuf S, Derancourt J, Casanova J, Durand-Clement M, le Peuch C, Haiech J, Cavadore J C
Centre de Recherches de Biochimie Macromoléculaire, LP 8402 du CNRS, INSERM U.249 Montpellier, France.
Toxicon. 1988;26(2):133-41. doi: 10.1016/0041-0101(88)90165-1.
Maitotoxin, a potent marine toxin isolated from toxic tropical dinoflagellates and poisonous fishes induces contraction of different smooth muscle preparations. Actions of maitotoxin on phosphoinositides and calcium metabolism were studied using a primary culture of aortic smooth muscle cells. Maitotoxin induced a very large increase of cytosolic calcium concentration as evaluated by fura-2 acetoxymethyl ester fluorescence. This increase was concomitant with stimulation of inositol-phosphate accumulation and loss of viability of aortic smooth muscle cells. These responses to maitotoxin were abolished in Ca2+-free medium, and were mimicked by saponin. Calcium ionophores or K+ depolarisation did not induce inositol-phosphate formation. These results suggest that maitotoxin acts by altering smooth muscle cells permeability allowing a sustained calcium influx which is able to activate inositol-phosphate formation and which is lethal for the cells.
刺尾鱼毒素是一种从有毒热带鞭毛藻和有毒鱼类中分离出的强效海洋毒素，可引起不同平滑肌制剂的收缩。利用主动脉平滑肌细胞原代培养研究了刺尾鱼毒素对磷酸肌醇和钙代谢的作用。通过fura-2乙酰氧甲酯荧光评估，刺尾鱼毒素可使细胞溶质钙浓度大幅升高。这种升高与肌醇磷酸积累的刺激以及主动脉平滑肌细胞活力的丧失同时发生。在无钙培养基中，对刺尾鱼毒素的这些反应被消除，且可被皂角苷模拟。钙离子载体或钾离子去极化不会诱导肌醇磷酸形成。这些结果表明，刺尾鱼毒素通过改变平滑肌细胞通透性起作用，允许持续的钙内流，这能够激活肌醇磷酸形成且对细胞具有致死性。
