Taleb O, Loeffler J P, Trouslard J, Demeneix B A, Kley N, Hollt V, Feltz P
Brain Res Bull. 1986 Nov;17(5):725-30. doi: 10.1016/0361-9230(86)90207-8.
We have examined the action of GABA on the electrical, secretory and synthetic activities of rat and porcine intermediate lobe (IL) cells in primary culture. Chloride and calcium currents were investigated using patch-clamp techniques. A chloride current activated by 1-100 microM isoguvacine, a specific GABA-A agonist, and antagonised by bicuculline and SR 95103 was recorded at the whole cell and single channel level current. Whole cell calcium currents were investigated and shown to be reduced by 40 microM cadmium, zero external calcium and 10 microM baclofen, a specific GABA-B receptor agonist. Both GABA-B receptor activation and use of calcium deficient medium inhibited peptide release from IL cells. Finally, pro-opiomelanocortin (POMC) mRNA levels were measured using a hybridization technique. Removal of calcium from the culture medium or long-term (48 hr) incubation with 10 microM GABA or muscimol (a mixed GABA-A and GABA-B agonist) significantly reduced POMC mRNA levels.
我们研究了γ-氨基丁酸（GABA）对原代培养的大鼠和猪垂体中间叶（IL）细胞的电活动、分泌活动及合成活动的作用。使用膜片钳技术研究了氯离子和钙离子电流。在全细胞和单通道水平记录到一种由1-100微摩尔异鹅膏蕈氨酸（一种特异性GABA-A激动剂）激活、并被荷包牡丹碱和SR 95103拮抗的氯离子电流。研究了全细胞钙离子电流，结果表明，40微摩尔镉、无细胞外钙离子以及10微摩尔巴氯芬（一种特异性GABA-B受体激动剂）可使其降低。GABA-B受体激活以及使用缺钙培养基均抑制IL细胞的肽释放。最后，使用杂交技术测定了阿黑皮素原（POMC）mRNA水平。从培养基中去除钙离子，或与10微摩尔GABA或蝇蕈醇（一种GABA-A和GABA-B混合激动剂）长期（48小时）孵育，均显著降低POMC mRNA水平。
