BARORECEPTOR/HORMONAL INTERACTIONS

室旁-脑干轴作为自主神经和 内分泌功能。我们假设催产素，一种多肽 这一途径中的递质，调节心血管反应， 这一点因钠的存在而更加突出。此外，我们认为中枢催产素 可能是一种重要的未被认识的神经内分泌调节剂 心血管和水矿物质平衡。最初的一个关键发现 授权期是PVN-脑干电路通过 压力感受器去神经支配在下丘脑引起慢性改变 神经分泌细胞，使它们对钠的影响过敏。 催产素系统对mRNA表达的反应增强 多肽的分泌尤其耐人寻味，因为 催产素作为心血管控制和盐之间的纽带作用 平衡。提出了一个研究项目，以研究肽能 PVN与脑干的相互作用及脑干的影响 催产素对心血管和交感神经功能的影响 压力感受器输入和中枢刺激对催产素基因表达的影响 以及催产素在压力感受器引起的盐摄入量变化中的作用。 该提案将采用一些技术，以便对 中枢神经功能、多肽mRNA表达、多肽分泌和 生理反应。微渗析将用于测量中央 全身催产素释放，微量注射用于研究 心血管和交感神经反应及原位杂交方法 用于评价细胞内mRNA水平的变化。具体的 该提案的目的是：1)通过以下方法研究PVN-脑干相互作用 探讨电刺激下丘脑室旁核对脑干催产素释放的影响 心血管参数2)检测催产素能 延髓迷走神经背侧复合体的脑干通路 自主神经流出调节与心血管功能3)评价 多肽信使核糖核酸对压力感受器去神经反应(时程)， 高渗盐水和血管紧张素及4)确定中枢的作用 压力感受器介导的盐摄入量变化中的催产素。

The paraventricular-brainstem axis acts as an integrator of autonomic and endocrine function. We hypothesize that oxytocin, a peptidergic transmitter in this pathway, modulates cardiovascular responses and that this is accentuated by sodium. Further we suggest that central oxytocin may be an important an unappreciated neuroendocrine modulator of cardiovascular and hydromineral balance. A key finding in the initial grant period was that interruption of this PVN-brainstem circuit via baroreceptor denervation produces chronic changes in the hypothalamic neurosecretory cells, making them hypersensitive to the effects of sodium. The increased response of the oxytocin system in terms of mRNA expression and peptide secretion is especially intriguing in view of the postulated role of oxytocin as a link between cardiovascular control and salt balance. A research program is proposed to study the peptidergic interactions between PVN and brainstem, the influence of brainstem oxytocin on cardiovascular and sympathetic nervous function, the influence of baroreceptor input and central stimulation on oxytocin mRNA expression and the role of oxytocin in baroreceptor-induced changes in salt intake. The proposal will employ techniques which will allow for the evaluation of central neuronal function, peptide mRNA expression, peptide secretion and physiological responses. Microdialysis will be used for measuring central and systemic oxytocin release, microinjection for the study of cardiovascular and sympathetic responses and in situ hybridization methods for the evaluating of the changes in cellular mRNA levels. The specific aims of the proposal are: 1) to study PVN-brainstem interactions by examining the effect of PVN stimulation on brainstem oxytocin release and cardiovascular parameters 2) to examine the role of oxytocinergic brainstem pathways to the dorsal vagal complex of the medulla in the regulation of autonomic outflow and cardiovascular function 3) to evaluate the peptide mRNA responses to baroreceptor denervation (time course), hypertonic saline and angiotensin and 4)To determine the role of central oxytocin in baroreceptor-mediated changes in salt intake.