Oset Gasque M J, Cañadas Correas S, Massó Córdoba J M, González González M P
Naunyn Schmiedebergs Arch Pharmacol. 1985 Jun;329(4):372-5. doi: 10.1007/BF00496370.
A sodium dependent GABA uptake system has been found in bovine adrenal medulla slices. This uptake has a Km of 83.19 +/- 38.45 microM and a Vmax of 9.20 +/- 1.36 pmol/min X mg of tissue. It was inhibited by nipecotic acid and 2,4-diaminobutyric acid (IC50 67 and 38.5 microM, respectively) but not by beta-alanine at concentrations up to 5 mM, a result which is similar to those found for the neuronal GABA uptake rather than the glial uptake. It is suggested that GABA uptake together with catabolic action of GABA-transaminase, also found in this tissue, could be regulating the GABA levels disposable for the proposed modulator role on catecholamine secretion of this amino acid in adrenal medulla.
在牛肾上腺髓质切片中发现了一种依赖钠的γ-氨基丁酸（GABA）摄取系统。这种摄取的米氏常数（Km）为83.19±38.45微摩尔，最大反应速度（Vmax）为9.20±1.36皮摩尔/分钟×毫克组织。它受到尼克酸和2,4-二氨基丁酸的抑制（半数抑制浓度[IC50]分别为67和38.5微摩尔），但在浓度高达5毫摩尔时不受β-丙氨酸的抑制，这一结果与在神经元而非胶质细胞中发现的GABA摄取情况相似。有人提出，GABA摄取以及该组织中也存在的GABA转氨酶的分解代谢作用，可能共同调节可用于该氨基酸对肾上腺髓质儿茶酚胺分泌的假定调节作用的GABA水平。
