Sloley B D, Kah O, Trudeau V L, Dulka J G, Peter R E
Department of Zoology, University of Alberta, Edmonton, Canada.
J Neurochem. 1992 Jun;58(6):2254-62. doi: 10.1111/j.1471-4159.1992.tb10971.x.
An isocratic high-performance liquid chromatographic technique was developed to measure levels of gamma-aminobutyric acid (GABA), glutamate, and taurine in the brain and pituitary of goldfish. Accuracy of this procedure for quantification of these compounds was established by evaluating anesthetic and postmortem effects and by selectively manipulating GABA concentrations by intraperitoneal administration of the glutamic acid decarboxylase (GAD) inhibitor 3-mercaptopropionic acid or the GABA transaminase inhibitor gamma-vinyl GABA. The technique provided a simple, rapid, and reliable method for evaluating the concentrations of these amino acids without the use of complex gradient chromatographic systems. To investigate the relationship between neurotransmitter amino acids and the control of pituitary secretion of gonadotropin, the effects of injection of taurine, GABA, or monosodium glutamate on GABA, glutamate, taurine, and, in some instances, monoamine concentrations in the brain and pituitary were evaluated and related to serum gonadotropin levels. Injection of taurine caused an elevation in serum gonadotropin concentrations. In addition, injection of the taurine precursor hypotaurine but not the taurine catabolite isethionic acid elevated serum gonadotropin levels. Intracerebroventricular injection of either GABA or taurine also elevated serum gonadotropin concentrations. Pretreatment of recrudescent fish with alpha-methyl-p-tyrosine reduced pituitary dopamine concentrations and also potentiated the serum gonadotropin response to taurine. Injection of monosodium glutamate caused an increase of glutamate content in the pituitary at 24 h; this was followed by a decrease at 72 h after administration. Pituitary GABA, taurine, and dopamine concentrations underwent a transient depletion after monosodium glutamate administration, and this was associated with an elevation of serum gonadotropin content.(ABSTRACT TRUNCATED AT 250 WORDS)
开发了一种等度高效液相色谱技术，用于测量金鱼脑和垂体中γ-氨基丁酸（GABA）、谷氨酸和牛磺酸的水平。通过评估麻醉和死后效应，以及通过腹腔注射谷氨酸脱羧酶（GAD）抑制剂3-巯基丙酸或GABA转氨酶抑制剂γ-乙烯基GABA选择性地控制GABA浓度，确定了该程序对这些化合物定量的准确性。该技术提供了一种简单、快速且可靠的方法，无需使用复杂的梯度色谱系统即可评估这些氨基酸的浓度。为了研究神经递质氨基酸与垂体促性腺激素分泌控制之间的关系，评估了注射牛磺酸、GABA或谷氨酸钠对脑和垂体中GABA、谷氨酸、牛磺酸以及某些情况下单胺浓度的影响，并将其与血清促性腺激素水平相关联。注射牛磺酸导致血清促性腺激素浓度升高。此外，注射牛磺酸前体次牛磺酸而非牛磺酸分解代谢物羟乙磺酸可提高血清促性腺激素水平。脑室内注射GABA或牛磺酸也会提高血清促性腺激素浓度。用α-甲基-p-酪氨酸预处理复发鱼可降低垂体多巴胺浓度，并增强血清促性腺激素对牛磺酸的反应。注射谷氨酸钠在24小时时导致垂体中谷氨酸含量增加；给药后72小时后随之下降。注射谷氨酸钠后，垂体GABA、牛磺酸和多巴胺浓度短暂耗尽，这与血清促性腺激素含量升高有关。（摘要截断于250字）
