Lavoute C, Weiss M, Risso J J, Rostain J C
Aix-Marseille University, UMR-MD2, Disoxy et Suractivité, Faculté de Médecine Nord, Bd Pierre Dramard, 13015, Marseille, France.
Institut de Recherche Biomedicale des Armées, HIA Ste Anne, Toulon, France.
Neurochem Res. 2017 Apr;42(4):1116-1122. doi: 10.1007/s11064-016-2145-0. Epub 2016 Dec 28.
Hyperbaric oxygen induced in rats a decrease in striatal dopamine levels. Such decrease could be a result of changes in glutamatergic and GABAergic controls of the dopaminergic neurons into the Substantia Nigra Pars Compacta. The aim of this study was to determine the role of gluatamatergic and Gama-Amino-Butyric-Acid neurotransmissions in this alteration. Dopamine-sensitive electrodes were implanted into the striatum under general anesthesia. After one week rest, awaked rats were exposed to oxygen-nitrogen mixture at a partial pressure of oxygen of 3 absolute atmospheres. Dopamine level was monitored continuously (every 3 min) by in vivo voltammetry with multifiber carbon electrodes before and during hyperbaric oxygen exposure. Hyperbaric oxygen induced a decrease in dopamine level in relationship with the increase in partial pressure of oxygen (-40% at 3 ATA). The used of N-Methyl-D-Aspartate, agonist of glutamatergic N-Methyl-D-Aspartate receptors did not improve considerably this change and gabazine antagonist of Gama-Amino-Butyric-Acid-a receptors induced some little alteration of this change. These results suggest the involvement of other mechanisms.
高压氧可使大鼠纹状体多巴胺水平降低。这种降低可能是由于黑质致密部多巴胺能神经元的谷氨酸能和γ-氨基丁酸能调控发生变化所致。本研究的目的是确定谷氨酸能和γ-氨基丁酸神经传递在这种改变中的作用。在全身麻醉下将多巴胺敏感电极植入纹状体。休息一周后，将清醒的大鼠暴露于氧分压为3个绝对大气压的氧氮混合气体中。在高压氧暴露前和暴露期间，用多纤维碳电极通过体内伏安法连续监测多巴胺水平（每3分钟一次）。高压氧导致多巴胺水平降低，且与氧分压升高相关（在3个绝对大气压时降低40%）。谷氨酸能N-甲基-D-天冬氨酸受体激动剂N-甲基-D-天冬氨酸的使用并未显著改善这种变化，而γ-氨基丁酸-A受体拮抗剂加巴嗪仅引起了这种变化的一些微小改变。这些结果提示还涉及其他机制。
