γ-氨基丁酸-A型受体拮抗剂对翘嘴鳜摄食及糖代谢的影响

Effect of γ-aminobutyric acid-A receptor antagonist on food intake and glucose metabolism in Chinese perch(Siniperca chuatsi)

以肉食性鱼类翘嘴鳜(Siniperca chuatsi)为研究对象,分别脑室注射二甲基亚砜(DMSO)+生理盐水(简称D)、DMSO+125μgγ-氨基丁酸GABA(简称DG)、DMSO+125μg GABA+20μg Bicuculline(GABA_A受体拮抗剂荷包牡丹碱)(简称DGB),研究GABA对翘嘴鳜摄食及糖代谢的影响。结果显示,DGB组的摄食量在0.5h、2h相比于D组(对照组)显著性下降,同时促食欲相关基因npy、agrp分别在0.5h和2h下调引起的抑制食欲与翘嘴鳜的低摄食保持一致。DG组的血糖含量相对于对照组显著下降,胰高血糖素显著上升,但cs、pc、pfk1基因的mRNA水平却并无显著性差异。试验结果表明,GABA_A受体拮抗剂能够抑制GABA与其受体结合从而抑制翘嘴鳜摄食,但GABA与糖代谢的偶联关系并不显著。

In this study,effect ofγ-aminobutyric acid(GABA)and GABA-A receptor antagonist on food intake and glucose metabolism in Chinese perch(Siniperca chuatsi)was investigated.Three groups including intracerebroventricular(ICV)injection of saline and DMSO(control,D),DMSO and 125μg GABA(DG),and DMSO,125μg GABA and 20μg antagonist bicuculline(DGB)were conducted.Food intake was significantly decreased in the DGB group at 0.5 h and 2 h post-injection compared with the D(control)group.Furthermore,the mRNA levels of npy and agrp were decreased significantly,which was coincident with lower food intake in Chinese perch.Blood glucose content was significantly decreased at 0.5 h post-injection,but the mRNA levels of cs,pc and pfk1 were not significant changed.The result of co-injection of GABA with bicuculline indicated that GABA acts as an orexigenic factor and further research about GABA on glucose metabolism is needed in Chinese perch.