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


CONCLUSIONS
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.
Fan
X T
XT
Department of Neurobiology, Third Military Medical University, Chongqing 400038, China. xufanhaitang@public.cta.cq.cn
Ruan
H Z
HZ
Xu
H W
HW
Zhang
J H
JH
Wu
X G
XG
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology*; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology*; D005260:Female; D018756:GABA Antagonists / Q000494:pharmacology; D007031:Hypothalamus / Q000166:cytology*; D000860:Hypoxia / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D013004:Somatostatin / Q000235:genetics / Q000378:metabolism*
D018756:GABA Antagonists; D012333:RNA, Messenger; D016194:Receptors, N-Methyl-D-Aspartate; D013004:Somatostatin; D015763:2-Amino-5-phosphonovalerate; D001640:Bicuculline