Effect of avermectin (AVM) on the expression of γ -aminobutyric acid A receptor (GABA_A R) in Carassius gibelio (Bloch, 1782)

Abstract

This study describes the effect of avermectin (AVM) on the expression of c-aminobutyric acid A receptor (GABA A R) in Carassius gibelio. To assess the specific expression of GABA A R in the brain, gonads, liver, kidneys, heart, muscles, and skin of C. gibelio, the expression of GABA A R a1 subunit (GABA A Ra1) was measured by Western blotting. To study the effects of AVM on the expression of GABA A R, the median lethal concentration (LC 50 ) at 24, 48, and 96 h of AVM was determined and the expression of GABA A R in the brain, liver, and kidneys of the corresponding C. gibelio evaluated by Western blotting and immunohistochemistry. The results show that GABA A R was expressed in the brain, gonads, liver, kidneys, heart, intestines, muscles, and skin, while primarily distributed in the central nervous system and moderately distributed in peripheral tissues. The expression of GABA A R in the brain, liver, and kidney tissues of C. gibelio was increased with the treatment of AVM at 24 h LC 50 , but attenuated by the treatment of AVM at 48 h LC 50 and 96 h LC 50 . This suggests a threshold effect of AVM.