Acs Z, Zsom L, Mergl Z, Makara G B
Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest.
Life Sci. 1993;52(21):1733-9. doi: 10.1016/0024-3205(93)90482-i.
Growth hormone (GH) secretion of the neonatal pituitary is stimulated by tau-aminobutyric acid (GABA) (1,2). Since in most cases GABA is known to act by increasing postsynaptic membrane permeability to chloride ions we tested the importance of chloride channel activation in the GH stimulatory effect of GABA in the neonatal pituitary. In the absence of chloride in the superfusion medium GABA was without effect on GH secretion of the neonatal pituitaries and its effect was attenuated by chloride channel inhibitors. The effect of growth hormone releasing hormone (GHRH) on GH secretion was attenuated in the chloride-free media, but it was not affected by simultaneous administration of chloride channel blockers. The present study indicates that GH stimulatory effect of GABA in the neonatal pituitaries might involve chloride channel activation probably resulting in secondary activation of calcium channels.
γ-氨基丁酸（GABA）可刺激新生垂体分泌生长激素（GH）(1,2)。由于在大多数情况下，已知GABA通过增加突触后膜对氯离子的通透性来发挥作用，因此我们测试了氯离子通道激活在GABA对新生垂体GH刺激作用中的重要性。在灌注培养基中缺乏氯离子的情况下，GABA对新生垂体的GH分泌没有影响，其作用会被氯离子通道抑制剂减弱。生长激素释放激素（GHRH）对GH分泌的作用在无氯培养基中减弱，但同时给予氯离子通道阻滞剂对其没有影响。本研究表明，GABA对新生垂体的GH刺激作用可能涉及氯离子通道激活，可能导致钙通道的继发性激活。
