Cortisol Extraction from Sturgeon Fin and Jawbone Matrices

Jalil Ghassemi Nejad; Mohammad Ataallahi; Mohammad H. Salmanzadeh; Kyung T. Park; Hong G. Lee; Alireza Shoae; Atieh Rahimi; Kyung I. Sung; Kyu H. Park

doi:10.3791/59961

Method Article

Cortisol Extraction from Sturgeon Fin and Jawbone Matrices

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DOI:

10.3791/59961

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September 10th, 2019

Jalil Ghassemi Nejad¹^,² , Mohammad Ataallahi¹ , Mohammad H. Salmanzadeh³ , Kyung T. Park³ , Hong G. Lee²^,⁴ , Alireza Shoae⁵ , Atieh Rahimi⁶ , Kyung I. Sung¹ , Kyu H. Park¹

¹College of Animal Life Sciences, Kangwon National University, ²Team of An Educational Program for Specialists in Global Animal Science, Brain Korea 21 Plus Project, Konkuk University, ³Persian Gesture, ⁴Department of Animal Science and Technology, College of Animal Bioscience and Technology, Konkuk University, ⁵Department of Animal Science, Animal Physiology, AgResearch, ⁶Faculty of Agriculture, Animal Science Department, Ferdowsi University of Mashhad

Summary

In this study, we present a protocol for cortisol extraction from the fin and jawbone of sturgeon species. Fin and jawbone cortisol levels were further examined by comparing two washing solvents followed by ELISA assays. This study piloted the feasibility of jawbone cortisol as a novel stress indicator.

Abstract

The aims of this study were to develop a technique for the extraction of cortisol from sturgeon fins using two washing solvents (water and isopropanol) and quantify any differences in fin cortisol levels among three main sturgeon species. Fins were harvested from 19 sacrificed sturgeons including seven beluga (Huso huso), seven Siberian (Acipenser baerii), and five sevruga (A. stellatus). The sturgeons were raised in Iranian farms for 2 years (2017-2018), and cortisol extraction analysis was conducted in South Korea (January-February 2019). Jawbones from five H. huso were also used for cortisol extraction. Data were analyzed using the general linear model (GLM) procedure in the SAS environment. The intra- and inter-assay coefficients of variation were 14.15 and 7.70, respectively. Briefly, the cortisol extraction technique involved washing the samples (300 ± 10 mg) with 3 mL of solvent (ultrapure water and isopropanol) twice, rotation at 80 rpm for 2.5 min, air-drying the washed samples at room temperature (22-28 °C) for 7 days, further drying the samples using a bead beater at 50 Hz for 32 min and grinding them into powder, applying 1.5 mL methanol to the dried powder (75 ± 5 mg), and slow rotation (40 rpm) for 18 h at room temperature with continuous mixing. Following extraction, samples were centrifuged (9,500 x g for 10 min), and 1 mL supernatant was transferred into a new microcentrifuge tube (1.5 mL), incubated at 38 °C to evaporate the methanol, and analyzed via enzyme-linked immunosorbent assay (ELISA). No differences were observed in fin cortisol levels among species or in fin and jawbone cortisol levels between washing solvents. The results of this study demonstrate that the sturgeon jawbone matrix is a promising alternative stress indicator to solid matrices.

Introduction

Cortisol is a reliable indicator of animal stress. Cortisol extraction provides a valid framework for researchers to monitor stress levels and general patterns in stressors. For example, previous studies have conducted methodological validation of hair cortisol measurements using various methods in humans¹^,², monkeys³^,⁴, cattle⁵, sheep⁶, and goldfish⁷^,⁸. In fish species, cortisol measurements in matrices such as scales, skin mucus, feces, and bloo....