Sommer C V, Binkowski F P, Schalk M A, Bartos J M
Department of Biological Sciences, University of Wisconsin--Milwaukee 53201.
Vet Hum Toxicol. 1986;28 Suppl 1:45-54.
The effects of environmental stress conditions on the defense response of rainbow trout following a four week exposure to subacute levels of un-ionized ammonia or temperatures 5 C above and 5 C below the temperature optimum (15 C) were investigated. These experimental studies can serve as a model to evaluate the metabolic response of fish to external agents (e.g., drugs, vaccines) under environmental conditions seen in the culture of fish. Blood and tissue immune parameters measured include hematocrits, antibody levels and differentiation of white blood cell populations in tissue imprints of the anterior kidney. These analyses were compared to the growth parameter, average percent weight gain. Fish given primary and secondary immunization with a bacterial vaccine (Aeromonas hydrophila) were exposed to sublethal concentrations of un-ionized ammonia of 0.2, 0.3 or 0.4 mg/ml. Fish exposed to the higher concentrations of ammonia showed a decrease in growth compared to control fish. Several significant changes were observed in the leukocytes of the anterior kidney at the various concentrations of ammonia tested. A decrease in antibody titers to A hydrophila was seen at the two higher concentrations of ammonia. In a second study, the effects of non-optimum temperature conditions (10 C and 20 C) were compared with an optimum temperature (15 C). Fish held at sub-optimum temperatures had significantly lower hematocrits than the control fish maintained at 15 C. Several significant changes were also seen in the anterior kidney leukocytes. Antibody titers to A hydrophila were significantly lower at the end of the stressing period in the trout maintained at 10 C compared to the immunized controls at 15 C. In contrast, fish held at 20 C had significantly higher antibody titers than did the immunized controls. Compared to controls, fish growth was increased at 10 C and decreased at 20 C. These studies confirm that environmental factors can induce stress and affect the metabolism and health of the fish.
研究了环境应激条件对虹鳟鱼防御反应的影响，虹鳟鱼在亚急性水平的未电离氨中暴露四周，或在比最适温度（15℃）高5℃和低5℃的温度下暴露四周。这些实验研究可作为一个模型，用于评估在鱼类养殖中常见的环境条件下，鱼类对外部因素（如药物、疫苗）的代谢反应。所测量的血液和组织免疫参数包括血细胞比容、抗体水平以及前肾组织印片中白细胞群体的分化情况。将这些分析结果与生长参数平均体重增加百分比进行比较。用细菌疫苗（嗜水气单胞菌）进行初次和二次免疫的鱼，暴露于0.2、0.3或0.4毫克/毫升的亚致死浓度未电离氨中。与对照鱼相比，暴露于较高浓度氨中的鱼生长速度下降。在测试的不同氨浓度下，前肾白细胞出现了一些显著变化。在两个较高氨浓度下，针对嗜水气单胞菌的抗体滴度下降。在第二项研究中，将非最适温度条件（10℃和20℃）的影响与最适温度（15℃）进行了比较。处于次最适温度下的鱼的血细胞比容明显低于维持在15℃的对照鱼。前肾白细胞也出现了一些显著变化。与15℃的免疫对照鱼相比，在应激期结束时，维持在10℃的虹鳟鱼针对嗜水气单胞菌的抗体滴度明显较低。相比之下，处于20℃的鱼的抗体滴度明显高于免疫对照鱼。与对照相比，鱼在10℃时生长加快，在20℃时生长减慢。这些研究证实，环境因素可诱导应激并影响鱼类的代谢和健康。
