AP-V和荷包牡丹碱对急性低压性低氧大鼠下丘脑内生长抑素阳性神经元的影响(英文)

目的:研究2-Amino-5-phosphonovalerate-pharmacology(AP-V)和荷包牡丹碱对急性低压性低氧大鼠下丘脑内生长抑素(SST)阳性神经元的影响。方法:用免疫组织化学和原位杂交技术检测大鼠下丘脑内SST-IR和SS mRNA阳性神经元数。结果:急性低氧引起下丘脑室周核(PeV)、室旁核(PVN)、弓状核(ARC)SST-IR和SS mRNA阳性神经元数明显增多,该效应可被NMDA受体拮抗剂AP-V(10μg,icv)明显抑制;而GABA_A受体拮抗剂荷包牡丹碱(1.5mg·kg~(-1),ip)则使其增强。结论:这些结果表明下丘脑内的生长抑素参与了急性低压低氧反应,且谷氨酸和GABA分别通过NMDA受体与GABA_A受体影响下丘脑内生长抑素的释放与合成。

Effects of AP-V and bicuculline on somatostatin-positive neurons in hypothalamus of rats subjected to acute hypobaric hypoxia

AIM: To investigate the effects of 2-amino-5-phosphonovalerate-pharmacology (AP-V) and bicuculline on somatostatin (SST)-positive neurons in hypothalamus of rats subjected to acute hypobaric hypoxia. METHODS: SST-immunoreactivity (IR) and somatostatin mRNA (SS mRNA)-positive neurons were measured by immunohistochemistry and in situ hybridization methods. RESULTS: Compared with control rats, SST-IR and SS mRNA-positive neurons in hypothalamic periventricular nucleus (PeV), paraventricular nucleus (PVN), and arcuate nucleus (ARC) increased after acute hypobaric hypoxia for 6 h (P < 0.01), and these effects were markedly inhibited by AP-V (10 microg, icv), a highly selective N-methyl-D-aspartate (NMDA) receptor antagonist, whereas were strongly enhanced by bicuculline (1.5 mg/kg, ip), a gamma-aminobutyric acid (GABAA) receptor antagonist. CONCLUSION: SST possibly participates in acute hypoxic reaction in hypothalamus, furthermore, glutamate and GABA can affect somatostatin release and synthesis in hypothalamus through NMDA and GABAA receptors respectively.