Gaete V, Canelo E, Lagos N, Zambrano F
Departamento de Biología, Facultad de Ciencias, Universided de Chile, Santiago, Chile.
Toxicon. 1994 Jan;32(1):121-7. doi: 10.1016/0041-0101(94)90028-0.
A microsomal fraction enriched in ion pump enzymes was isolated from the gill of the carp (Cyprinus carpio Linneo). Mg(2+)-dependent (Na+ + K+), Na+, HCO3- and Ca(2+)-stimulated ATPase activities were studied following treatment with microcystin-LR-like toxin, the major toxic component isolated from Microcystis aeruginosa culture. These enzyme activities were inhibited in a dose-dependent manner. The maximum inhibition of each enzyme, induced with nM concentration of the toxin, was similar to that produced by inhibitors specific for each ATPase activity. The Mg(2+)-ATPase activity and non-specific hydrolysis of ATP were unaffected. These results strongly suggest that the massive fish death during M. aeruginosa blooms may result from the loss of ion homeostatic processes produced by the inhibitory action of microcystin on the ion pumps of gill chloride cells.
从鲤鱼（鲤科鲤属鲤种）的鳃中分离出富含离子泵酶的微粒体部分。在用微囊藻毒素-LR样毒素（从铜绿微囊藻培养物中分离出的主要有毒成分）处理后，研究了镁离子依赖的（钠离子+钾离子）、钠离子、碳酸氢根离子和钙离子刺激的ATP酶活性。这些酶活性以剂量依赖的方式受到抑制。用纳摩尔浓度的毒素诱导的每种酶的最大抑制作用，与每种ATP酶活性特异性抑制剂产生的抑制作用相似。镁离子ATP酶活性和ATP的非特异性水解不受影响。这些结果强烈表明，铜绿微囊藻大量繁殖期间鱼类的大量死亡，可能是由于微囊藻毒素对鳃氯细胞离子泵的抑制作用导致离子稳态过程丧失所致。
