Tanaka Junichi, Hatakenaka Satoko, Miyakubo Hiroko, Nomura Masahiko
Department of Curriculum, Teaching and Memory, Naruto University of Education, Takashima, Naruto-cho, Naruto, Tokushima 772-8502, Japan.
Brain Res Bull. 2003 May 15;60(3):233-40. doi: 10.1016/s0361-9230(03)00039-x.
The present study was designed to examine whether noradrenergic projections from the A1 cell group in the ventrolateral medulla to the median preoptic nucleus (MnPO) transmit information from the peripheral baroreceptors. In urethane-anesthetized male rats, extracellular concentrations of noradrenaline (NA) in the region of the MnPO in response to hemorrhage (5 or 10 ml/kg) were monitored with in vivo microdialysis methods. Hemorrhage significantly increased the NA release in the MnPO area. The enhancement of NA release in the MnPO area caused by hemorrhage was significantly attenuated by previous injections of the local anesthetic lidocaine (2 %, 0.2 microl), but not by saline (0.2 microl), into the A1 region. These results suggest that the noradrenergic projections from the A1 region are important for carrying the peripheral baroreceptor information to the MnPO.
本研究旨在探讨延髓腹外侧A1细胞群至视前正中核（MnPO）的去甲肾上腺素能投射是否传递来自外周压力感受器的信息。在用乌拉坦麻醉的雄性大鼠中，采用体内微透析方法监测MnPO区域去甲肾上腺素（NA）的细胞外浓度对出血（5或10 ml/kg）的反应。出血显著增加了MnPO区域的NA释放。先前向A1区域注射局部麻醉剂利多卡因（2%，0.2微升）可显著减弱出血引起的MnPO区域NA释放增强，但注射生理盐水（0.2微升）则无此作用。这些结果表明，来自A1区域的去甲肾上腺素能投射对于将外周压力感受器信息传递至MnPO很重要。
