The GH/IGF-I axis influences many aspects of salmonid life history and is involved in a variety of physiological processes that are related to somatic growth (e.g., reproduction, smoltification, and the response to fasting and stress). As such, fisheries studies utilize GH/IGF-I axis components as indicators of growth and metabolic status. This study established time-resolved fluoroimmunoassays (TR-FIAs) for rainbow trout plasma GH and IGF-I using commercially available reagents. For the GH TR-FIA, the ED₈₀ and ED₂₀ were 0.6 and 28.1 ng/mL, the minimum detection limit was 0.2 ng/mL, and the intra- and inter-assay coefficients of variation (%CV) were 4.1% and 13.4%, respectively. Ethanol remaining from acid-ethanol cryoprecipitation (AEC) of plasma samples to remove IGF binding proteins reduced binding and increased variability in the IGF-I TR-FIA. Drying down and reconstituting extracted samples restored binding and reduced variability. The extraction efficiency of IGF-I standards through AEC, drying down, and reconstitution did not vary over the working range of the assay. For the IGF-I TR-FIA, the ED₈₀ and ED₂₀ were 0.2 and 6.5 ng/mL, the minimum detection limit was 0.03 ng/mL, and the intra- and inter-assay %CV were 3.0% and 6.5%, respectively. Biological validation was provided by GH injection and fasting studies in rainbow trout. Intraperitoneal injection with bovine GH increased plasma IGF-I levels. Four weeks of fasting decreased body weight, increased plasma GH levels, and decreased plasma IGF-I levels. The GH and IGF-I TR-FIAs established herein provide a cost-comparable, non-radioisotopic method for quantifying salmonid plasma GH and IGF-I using commercially available reagents.

GH / IGF-I轴影响鲑鱼的生活史的许多方面，并参与与体细胞生长相关的各种生理过程（例如生殖，糖化以及对禁食和压力的反应）。因此，渔业研究利用GH / IGF-I轴成分作为生长和代谢状况的指标。这项研究使用市售试剂建立了虹鳟血浆GH和IGF-1的时间分辨荧光免疫测定法（TR-FIA）。对于GH TR-FIA，ED ₈₀和ED ₂₀分别为0.6和28.1 ng / mL，最小检出限为0.2 ng / mL，测定内和测定间变异系数（％CV）分别为4.1％和13.4％。血浆样品的酸-乙醇低温沉淀（AEC）中残留的乙醇可去除IGF结合蛋白，从而降低了IGF-I TR-FIA的结合力并增加了变异性。干燥并重建提取的样品可恢复结合并降低变异性。通过AEC对IGF-I标准品的提取效率，干燥和重构在测定的工作范围内没有变化。对于IGF-I TR-FIA，ED ₈₀和ED ₂₀分别为0.2和6.5 ng / mL，最小检出限为0.03 ng / mL，测定内和测定间％CV分别为3.0％和6.5％。GH注射和虹鳟鱼的禁食研究提供了生物学验证。牛GH腹膜内注射可增加血浆IGF-I水平。禁食四周可减轻体重，增加血浆GH水平并降低血浆IGF-1水平。本文建立的GH和IGF-I TR-FIA提供了一种成本可比的非放射性同位素方法，用于使用市售试剂定量鲑鱼血浆GH和IGF-I。