Campus Universitário de Iturama, Universidade Federal do Triângulo Mineiro, Iturama, MG, Brasil.
Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
Aquat Toxicol. 2022 May;246:106144. doi: 10.1016/j.aquatox.2022.106144. Epub 2022 Mar 14.
Water quality is essential for successful aquaculture. For freshwater shrimp farming, ammonia concentrations can increase considerably, even when culture water is renewed frequently, consequently increasing the risk of ammonia intoxication. We investigated ammonia lethality (LC-96 h) in a hololimnetic population of the Amazon River shrimp Macrobrachium amazonicum from the Paraná/Paraguay River basin, including the effects of exposure to 4.93 mg L total ammonia concentration on gill (Na, K)-ATPase activity. The mean LC-96 h was 49.27 mg L total ammonia, corresponding to 1.8 mg L un-ionized ammonia. Except for NH affinity that increased 2.5-fold, that of the gill (Na, K)-ATPase for ATP, Mg, Na, K and ouabain was unchanged after ammonia exposure. Western blotting of gill microsomal preparations from fresh caught shrimps showed a single immunoreactive band of ≈110 kDa, corresponding to the gill (Na, K)-ATPase α-subunit. Ammonia exposure increased (Na, K)-ATPase activity by ≈25%, coincident with an additional 130 kDa α-subunit immunoreactive band, and increased K-stimulated and V(H)-ATPase activities by ≈2.5-fold. Macrobrachium amazonicum from the Paraná/Paraguay River basin is as tolerant to ammonia as are other Amazon River basins populations, showing toxicity comparable to that of marine crustaceans.
水质对于成功的水产养殖至关重要。对于淡水虾养殖，即使频繁更新养殖水，氨浓度也会显著增加，从而增加氨中毒的风险。我们研究了来自巴拉那/巴拉圭河流域的亚马逊河虾 Macrobrachium amazonicum 全湖种群的氨致死性（96 小时 LC），包括暴露于 4.93 毫克/升总氨浓度对虾鳃（Na，K）-ATP 酶活性的影响。96 小时 LC 的平均值为 49.27 毫克/升总氨，相当于 1.8 毫克/升未离解氨。除了 NH 亲和力增加了 2.5 倍外，暴露于氨后，虾鳃（Na，K）-ATP 酶对 ATP、Mg、Na、K 和哇巴因的亲和力没有变化。从新鲜捕获的虾的鳃微体制剂进行的 Western 印迹显示，单一免疫反应性带约为 110 kDa，对应于虾鳃（Na，K）-ATP 酶α亚基。氨暴露增加了（Na，K）-ATP 酶活性约 25%，同时出现了另外一个 130 kDa 的α亚基免疫反应性带，并使 K 刺激和 V（H）-ATP 酶活性增加了约 2.5 倍。来自巴拉那/巴拉圭河流域的 Macrobrachium amazonicum 与其他亚马逊河流域种群一样耐受氨，其毒性与海洋甲壳类动物相当。
