Effect of ammonia to fish neutrophils and its permissible level

将0.2ml细菌溶液（大肠杆菌，5 mg/ml）在25 μ C-WT下注射到罗非鱼的鱼鳔中。在注射后24小时，通过注射器从膀胱腔中抽出渗出液。液体中含有大量白细胞，其中中性粒细胞占> 97%。将0.011和0.023ppm的氨分别加入到NH_4 + 0.0，0.011和0.023ppm的NH_3平衡盐溶液中。在体外氨毒性试验中，氨抑制了中性粒细胞的吞噬能力。在活体试验中，将罗非鱼在25 ℃的氨水（以NH 4+计，0、1和2 ppm，以NH3计，0、0.003和0.006ppm）中饲养一周。在该试验中，中性粒细胞生理学不受环境氨浓度的影响。在整个试验期内，尽管氨水浓度不同，但暴露于氨水中的鱼的血氨水平几乎相同。在活体氨毒性试验过程中，我们经常看到优势鱼对从属鱼的攻击行为。中性粒细胞的功能显着抑制相比，占主导地位的下属鱼。由于这种行为方面在鱼类免疫学中一直被忽视，免疫学家应该在未来发展它。

0.2ml of bacterial solution (E.coli, 5mg/ml) was injected into a swim bladder of tilapia under 25ﾟC-WT.At 24 hrs post-injection, the exudative fluid was withdrawn from the bladder lumen by a syringe. The fluid contained large numbers of leucocytes, in which neutrophils occupied >97%. This neutrophil isolation was also available to the other fresh- and seawater fishes.Ammonia was added to the neutrophils-Hanks balanced saline solution at the concentration of 0,1, and 2ppm (as NH4+.0,0.011, and 0.023ppm as NH3). In this in vitro ammonia toxicity, the ammonia depressed the phagocytic ability of neutrophils. For in vivo test, tilapia was kept in ammonia water (0,1, and 2ppm as NH4+, 0,0.003, and 0.006ppm as NH3) for one week under 25ﾟC.The neutrophils were isolated to analyze their physiology in the 0,1st, 3rd, and 7th day. In this test, the neutrophil physiology was not affected by the ambient ammonia concentrations. The blood ammonia levels of the fish exposed to the ammonia water were almost same through the whole test period despite the different water ammonia concentraions. This result is probably responsible for the noinfluence on the neutrophil physiology of the fish kept in ammonia water.On the process of in vivo ammonia toxicity test, we frequently saw aggressive behavior of a dominant fish to a subordinate one. The neutrophil function was drastically depressed in the subordinate fish compared to the dominant. Because this behavioral aspect has been overlooked in fish immunology so far, the immunologist should develop it in future.