Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, SP 14801-903, Brazil.
Neurosci Lett. 2013 Nov 27;556:32-6. doi: 10.1016/j.neulet.2013.09.045. Epub 2013 Oct 2.
Injection of l-glutamate (GLU) into the rostral ventrolateral medulla (RVLM) produces sympathetically-mediated pressor responses that depend on the integrity of the tissue surrounding the anteroventral third ventricle (AV3V region). The injection of angiotensin II (ANG II) or the cholinergic agonist carbachol into the RVLM also produces pressor responses. In the present study, we investigated if the lesion of the AV3V region affects the pressor responses to ANG II or carbachol injected into the RVLM in unanesthetized rats. Male Holtzman rats with sham or electrolytic AV3V lesions and a stainless steel cannula implanted into the RVLM were used. The pressor responses to ANG II (200ng/100nl) injected into the RVLM were reduced by acute (1 day) (12±3 vs. sham lesions: 26±4mmHg) or chronic (15 days) AV3V lesions (12±5 vs. sham lesions: 27±4mmHg), whereas acute or chronic AV3V lesions did not affect the pressor responses to carbachol (1nmol/100nl) injected into the RVLM. The present results suggest that the AV3V region modulates the excitability of the RVLM neurons involved with the pressor response produced by the activation of angiotensinergic mechanisms in this area.
将 L-谷氨酸（GLU）注射到延髓腹外侧头端（RVLM）会引起交感神经介导的升压反应，这种反应依赖于围绕前腹侧第三脑室（AV3V 区域）的组织完整性。将血管紧张素 II（ANG II）或胆碱能激动剂卡巴胆碱注射到 RVLM 也会引起升压反应。在本研究中，我们研究了 AV3V 区域的损伤是否会影响注入 RVLM 的 ANG II 或卡巴胆碱引起的升压反应在未麻醉大鼠中。使用了具有假手术或电解 AV3V 损伤以及植入 RVLM 的不锈钢套管的雄性霍尔茨曼大鼠。注入 RVLM 的 ANG II（200ng/100nl）引起的升压反应被急性（1 天）（12±3 对假手术损伤：26±4mmHg）或慢性（15 天）AV3V 损伤（12±5 对假手术损伤：27±4mmHg）减弱，而急性或慢性 AV3V 损伤不会影响注入 RVLM 的卡巴胆碱（1nmol/100nl）引起的升压反应。本研究结果表明，AV3V 区域调节了与该区域血管紧张素能机制激活引起的升压反应有关的 RVLM 神经元的兴奋性。
