SUPRABULBAR EFFECTS OF SINOAORTIC DENERVATION

去窦弓神经(SAD)大鼠有轻度高血压和不稳定 与身体运动和血浆升高相关的动脉压 加压素。最近的研究表明，酪氨酸羟化酶(TH) 尾状核的活性和多巴胺(DA)浓度降低 SAD大鼠核内TH活性也降低 黑质和视上核(SON)。因为黑质纹状体系统是一个 躯体运动神经整合的主要部位与中枢性DA 激动剂在某些形式的药物中有降低血压的作用 高血压，这一假说将被检验为减少DA代谢 黑质纹状体引起特有的身体运动相关压力 SAD大鼠不稳定，并导致其轻度高血压。 将DA激动剂微量注射到黑质纹状体 自由活动SAD和假手术对照组大鼠的动脉压 和心率都被持续记录下来。一种在线DEC计算机 将生成频率间隔直方图、平均值和标准差 血压和心率的数值。皮损对血流动力学的影响 还将对正常大鼠的黑质纹状体区域进行评估。另一个 需要检验的假设是，减少合成和释放 下丘脑儿茶酚胺抑制SAD患者加压素的分泌 老鼠。TH的体内外活性、释放和转化 将测量SON和室旁核中儿茶酚胺的含量。这个 黑质纹状体和黑质纹状体的生化改变的发病时间和持续时间 将对下丘脑区域进行研究。尾状核的变化也开始出现 将通过体内伏安法进行评估，在试点研究中表明 去窦弓神经释放DA。所有的生化分析都将是 灵敏、特异和放射性同位素。最后是免疫组织化学荧光 探测器将被用来寻找脑干之间投射的证据 与心血管调节和黑质相关的区域。

The sinoaortic denervated (SAD) rat has mild hypertension and labile arterial pressure associated with body movements and haselevated plasma vasopressin. Recent investigations revealed that tyrosine hydroxylase (TH) activity and dopamine (DA) concentration were reduced in the caudate nucleus of SAD rats and that TH activity was also reduced in substantia nigra and supraoptic nucleus (SON). Since the nigrostriatal system is a major site of somatomotor neural integration and since centrally active DA agonists have a blood pressure lowering effect in some forms of hypertension, the hypothesis will be tested that reduced DA metabolism in the nigrostriatum causes the characteristic body movement- related pressure lability of SAD rats and contributes to their mild hypertension. Microinjections of DA agonists will be made into the nigrostriatum of freely moving SAD and sham-operated control rats whose arterial pressure and heart rate are being continuously recorded. An on-line DEC computer will generate frequency-interval histograms, mean and standard deviation values of pressure and heart rate. Hemodynamic effects of lesioning nigrostriatal region of normal rats will also be evaluated. Another hypothesis to be tested is that reduced synthesis and release of catecholamines in the hypothalamus disinhibits vasopressin secretion in SAD rats. In vivo and in vitro TH activity, release and turnover of catecholamines in SON and paraventricular nucleus will be measured. The time of onset and duration of biochemical changes in both nigrostriatal and hypothalamic regions will be studied. Onset of changes in caudate also will be evaluated by in vivo voltammetry which, in pilot studies, indicated DA was released by sinoaortic denervation. All biochemical assays will be sensitive, specific and radioisotopic. Finally immunohistofluorescent probes will be used to look for evidence of projections between brain stem areas associated with cardiovascular regulation and the substantia nigra.