Universidade Estadual Paulista UNESP - Centro de Aquicultura, Campus de Jaboticabal, Via de Acesso Prof. Paulo Donato Castelane, S/N - Vila Industrial, Jaboticabal, São Paulo, 14884-900, Brazil.
Universidade Estadual Paulista UNESP - Centro de Aquicultura, Campus de Jaboticabal, Via de Acesso Prof. Paulo Donato Castelane, S/N - Vila Industrial, Jaboticabal, São Paulo, 14884-900, Brazil; Universidade Estadual Paulista UNESP - Faculdade de Ciências Agrárias e Veterinárias, Campus de Jaboticabal, Via de Acesso Prof. Paulo Donato Castelane, S/N - Vila Industrial, Jaboticabal, São Paulo, 14884-900, Brazil.
Fish Shellfish Immunol. 2019 Oct;93:1076-1083. doi: 10.1016/j.fsi.2019.07.068. Epub 2019 Jul 25.
In this study, we show that β-glucan can modulate cortisol release in fish. We simulated a common situation in aquaculture: the transport of fish followed by contact with an opportunistic pathogen and observed what effect glucan had on the immune and stress response in these conditions. Pacu (Piaractus mesopotamicus) were fed with a diet containing β-glucan (0.1%) for 15 days prior to transport followed by an injection with heat-killed Aeromonas hydrophila. We sampled fish before transport, at arrival and at 3 and 24 h after bacterial injection. β-Glucans are used in aquaculture and have a known immunostimulatory effect, which was observed in this study. The results showed that β-glucan modulated the plasma cortisol levels differently by increasing these levels up to 24 h after transport and preventing the increase caused by bacterial inoculum injection. In addition, β-glucan enhanced the activity of the complement system at 24 h and reduced the monocytes and lymphocytes number in peripheral blood at 3 and 24 h after bacterial inoculation. Our results suggest that β-glucan modulated a bidirectional interaction between the stress and the immune responses. The modulation of cortisol levels and the immunostimulation by β-glucan at different moments in our study suggest the compound has a protective effect by avoiding higher levels of the hormone and improving resistance against bacterial infection in pacu. These results add evidence to support the use of β-glucan as an immunomodulator in the aquaculture industry.
在这项研究中，我们表明β-葡聚糖可以调节鱼类的皮质醇释放。我们模拟了水产养殖中的常见情况：鱼类运输后接触机会性病原体，并观察葡聚糖在这些条件下对免疫和应激反应的影响。在运输前 15 天，我们用含有β-葡聚糖（0.1%）的饲料喂养食人鱼（Piaractus mesopotamicus），然后用加热杀死的嗜水气单胞菌进行注射。我们在运输前、到达时以及细菌注射后 3 和 24 小时采集鱼类样本。β-葡聚糖在水产养殖中被广泛应用，具有已知的免疫刺激作用，本研究也观察到了这一作用。结果表明，β-葡聚糖通过在运输后 24 小时内提高皮质醇水平，以及防止细菌接种引起的皮质醇水平升高，从而调节血浆皮质醇水平。此外，β-葡聚糖在 24 小时时增强了补体系统的活性，并在细菌接种后 3 和 24 小时减少了外周血中的单核细胞和淋巴细胞数量。我们的研究结果表明，β-葡聚糖调节了应激和免疫反应之间的双向相互作用。β-葡聚糖在本研究的不同时间点调节皮质醇水平和免疫刺激作用，表明该化合物具有保护作用，可避免激素水平升高，并提高食人鱼对细菌感染的抵抗力。这些结果为支持β-葡聚糖作为水产养殖中免疫调节剂的应用提供了更多证据。
