Ventral lamina terminalis mediates enhanced cardiovascular responses of rostral ventrolateral medulla neurons during increased dietary salt.
Ventral lamina terminalis mediates enhanced cardiovascular responses of rostral ventrolateral medulla neurons during increased dietary salt.
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DOI：
10.1161/hypertensionaha.108.127803
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发表时间：
2009-08
期刊：
影响因子：
--
通讯作者：
Stocker SD
中科院分区：
文献类型：
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作者：
Adams JM;Bardgett ME;Stocker SD
增加饮食中的盐可增强延髓头端腹外侧区（RVLM）诱发的交感神经兴奋和交感神经抑制反应。本研究的目的是确定是否前脑终板（LT）的神经元介导的RVLM的这些变化。对有和无LT病变的雄性Sprague-Dawley大鼠喂食正常食物，并给予水或0.9%NaCl 14-15天。将L-谷氨酸注射到RVLM中可使注射0.9%NaCl的假手术大鼠的肾交感神经活动（SNA）和动脉血压（ABP）显著增加。然而，这些差异并没有观察到腹侧LT损伤大鼠饮用0.9%氯化钠与水。当血管紧张素II或GABA注入RVLM时，观察到类似的结果。有趣的是，饮用0.9%但损伤仅限于终板血管器的动物亚组对L-谷氨酸或GABA的反应没有增强。与此形成鲜明对比的是，在急性腹侧LT病变或穹窿下器官慢性病变后，RVLM注射L-谷氨酸或GABA在饮用0.9% NaCl与水的动物中产生夸大的SNA和ABP反应。另外的实验表明，在摄入0.9%NaCl的大鼠中，血浆钠浓度和渗透压在夜间增加。这些结果表明，腹侧LT的神经元介导的能力，增加饮食中的盐，以提高RVLM交感神经元的反应。
Increased dietary salt enhances sympathoexcitatory and sympathoinhibitory responses evoked from the rostral ventrolateral medulla (RVLM). The purpose of the present study was to determine whether neurons of the forebrain lamina terminalis (LT) mediated these changes in the RVLM. Male Sprague-Dawley rats with and without LT lesions were fed normal chow and given access to water or 0.9% NaCl for 14-15 days. Unilateral injection of L-glutamate into the RVLM produced significantly larger increases in renal sympathetic nerve activity (SNA) and arterial blood pressure (ABP) of sham rats ingesting 0.9% NaCl versus water. However, these differences were not observed between ventral LT-lesioned rats drinking 0.9% NaCl versus water. Similar findings were observed when angiotensin II or GABA were injected into the RVLM. Interestingly, a subset of animals drinking 0.9% but with damage restricted to the organum vasculosum of the lamina terminalis did not show enhanced responses to L-glutamate or GABA. In marked contrast, RVLM injection of L-glutamate or GABA produced exaggerated SNA and ABP responses in animals drinking 0.9% NaCl versus water after an acute ventral LT lesion or chronic lesion of the subfornical organ. Additional experiments demonstrate plasma sodium concentration and osmolality were increased at night in rats ingesting 0.9% NaCl. These findings suggest that neurons of the ventral LT mediate the ability of increased dietary salt to enhance the responsiveness of RVLM sympathetic neurons.