抄録
The present study was done to investigate whether 0.3 M NaCl and water intake alters the release of serotonin (5-hydoxytryptamine, 5-HT) in the region of the lateral parabrachial nucleus (LPBN) in freely moving rats. The intake of 0.3 M NaCl and water was induced by subcutaneous administrations of the diuretic furosemide (FURO, 10 mg/kg) and the angiotensin converting enzyme inhibitor captopril (CAP, 5 mg/kg), and extracellular concentrations of 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) were measured using in vivo microdialysis methods. The intake of 0.3 M NaCl and water significantly increased the 5-HT and 5-HIAA levels in the LPBN area. The combined treatment with FURO and CAP caused significant decreases in the 5-HT and 5-HIAA concentrations in the LPBN area under the condition that 0.3 M NaCl and water are not available for drinking. These results suggest that the serotonergic system in the LPBN area may play an important role in the modulation of sodium appetite and thirst. [Jpn J Physiol 54 Suppl:S206 (2004)]
