ABSTRACT
Objective To research the mechanism or pathway through which Substance P(SP) inhibits r-aminobutyric acid(GABA) activated currents in bullfrog dorsal root ganglion(DRG) neurons.Method The experiment was conducted on freshly isolated bullfrog dorsal root ganglion neurons using a whole-cell patch-clamp technique.Results SP could caused a slow inward current when SP was applied to DRG neurons;SP could inhibits GABA-activated currents;The inhibition could be reduced largely when protein kinase C(PKC) inhibiter,1-(5-isoquinolinesulphorry)-2-methylpiperazine(H-7), was dialyzed in cell body.Conclusion The SP ton inhibit GABA-activated currents through protein kinase C.
ABSTRACT
AIM:To observe the effect of altitude hypoxia on ?-aminobutyric (GABA) content and prepro-somatostatin mRNA (PPS-mRNA) in the rat hypothalamus. METHODS: Using altitude hypoxia model,in situ hybridization and amino acid analyzer, the number of PPS-mRNA and GABA content in rat hypothalamus was determined. RESULTS:After altitude hypoxia, the contents of GABA in hypothalamus and the number of PPS-mRNA neurons in periventricular nucleus (PeVN), paraventricular nucleus (PaVN) and arcuate nucleus (ArcN) increased significiantly. Bicuculline, a GABA receptor antagonits, could enhance PPS-mRNA expression evoked by altitude hypoxia, but had no effect on GABA content. CONCLUSION: Altitude hypoxia can induce neurotransmitter imbalance of hypothalamus.