Del Tacca M, Blandizzi C, Bernardini M C, Martelli F, Della Longa A
Institute of Medical Pharmacology, Veterinary Medical School, Pisa, Italy.
Experientia. 1989 Aug 15;45(8):734-6. doi: 10.1007/BF01974572.
In order to investigate the role of peripheral GABA-B receptors, the effects of the putative GABA-B agonist baclofen on immunoreactive gastrin release from an isolated vascularly perfused rat stomach preparation were examined. The vascular infusion of baclofen at graded concentrations induced a dose-dependent increase in gastrin release; this was unaffected by the GABA-B antagonist delta-aminovaleric acid, but was fully prevented by the selective GABA-A antagonist bicuculline as well as by atropine or tetrodotoxin. These results suggest that the stimulant effects of baclofen are mediated by nervous cholinergic structures associated with GABA-A receptors, and indicate that this GABA-B agonist must be regarded as a partial agonist of peripheral GABA-A receptors.
为了研究外周GABA-B受体的作用，我们检测了假定的GABA-B激动剂巴氯芬对从离体血管灌注大鼠胃制备物中释放的免疫反应性胃泌素的影响。以分级浓度进行血管内输注巴氯芬可诱导胃泌素释放呈剂量依赖性增加；这不受GABA-B拮抗剂δ-氨基戊酸的影响，但可被选择性GABA-A拮抗剂荷包牡丹碱以及阿托品或河豚毒素完全阻断。这些结果表明，巴氯芬的刺激作用是由与GABA-A受体相关的神经胆碱能结构介导的，并表明这种GABA-B激动剂必须被视为外周GABA-A受体的部分激动剂。
