Moreover, in tilapia, there was no additional residue
found in the GR1 and GR2 isoforms. Furthermore, the plasma levels
of cortisol in stressed fish were above ED50 for each isoform,
whereas in non-stressed fish, the plasma levels were above ED50
only for GR2, which indicated that cortisol would not bind to the
GR1 in non- or mildly stressful conditions and that both GR1 and
GR2 may be activated in highly stressful conditions [7,35,47]