Abrahám I, Juhász G, Kékesi K A, Kovács K J
Laboratory of Molecular Neuroendocrinology, Institute of Experimental Medicine, Budapest, Hungary.
Stress. 1998 Jul;2(3):171-81. doi: 10.3109/10253899809167281.
Effect of ether stress on dialysate concentration of extracellular amino acids in the hippocampus was studied by microdialysis in freely moving rats that have been either sham operated (SHAM) or adrenalectomized and supplemented with subcutaneous steroid pellets (ADX+CORT) providing constant corticosterone (CORT) plasma levels. In SHAM rats, ether stress resulted in a peak of glutamate and taurine 30 min after stress, while extracellular aspartate concentration was increased 120 min after challenge. These changes in amino acid levels as well as in glutamate/glutamine ratio were paralleled by stress-induced rise of plasma CORT. No significant alterations were detected in the concentration of hippocampal arginine, alanine, glycine, glutamine, threonine or serine. In contrast to SHAM animals, ether stress failed to have an effect on dialysate concentration of amino acid transmitters in the hippocampus of adrenalectomized rats supplemented with 50 mg CORT-pellets. Our results demonstrate that ether stress alters aspartate, glutamate, glutamate/glutamine ratio and taurine concentration in the hippocampus and indicate that stress-induced CORT release in plasma may be responsible for these amino acid alterations. These changes may also contribute to negative feedback effect of CORT on hypothalamo-pituitary-adrenocortical (HPA) axis via the hippocampus during stress.
通过微透析技术，在自由活动的大鼠中研究了乙醚应激对海马细胞外氨基酸透析液浓度的影响。这些大鼠要么接受了假手术（SHAM），要么进行了肾上腺切除并皮下植入类固醇药丸（ADX+CORT）以维持血浆皮质酮（CORT）水平恒定。在SHAM大鼠中，乙醚应激导致应激后30分钟谷氨酸和牛磺酸浓度达到峰值，而天冬氨酸细胞外浓度在刺激后120分钟升高。氨基酸水平以及谷氨酸/谷氨酰胺比值的这些变化与应激诱导的血浆CORT升高平行。未检测到海马精氨酸、丙氨酸、甘氨酸、谷氨酰胺、苏氨酸或丝氨酸浓度有显著变化。与SHAM动物相反，乙醚应激对补充了50mg CORT药丸的肾上腺切除大鼠海马中氨基酸递质的透析液浓度没有影响。我们的结果表明，乙醚应激会改变海马中天冬氨酸、谷氨酸、谷氨酸/谷氨酰胺比值和牛磺酸浓度，并表明应激诱导的血浆CORT释放可能是这些氨基酸变化的原因。这些变化也可能在应激期间通过海马对CORT对下丘脑-垂体-肾上腺皮质（HPA）轴的负反馈作用有贡献。
