Okada J, Takayama K, Xiong Y, Miura M
Department of Physiology 1st Division, Gunma University School of Medicine, Maebashi-shi, Japan.
J Auton Nerv Syst. 1994 Oct;49(2):171-82. doi: 10.1016/0165-1838(94)90136-8.
To study the influence of humoral control peptides on medullary vasomotor control neurons, angiotensin II (AII), arginine vasopressin (AVP) and atrial natriuretic peptide (ANP) were microinjected into three vasomotor control areas, i.e., the area postrema (AP), the nucleus tractus solitarii (NTS) and the rostral ventrolateral medulla (RVLM), of spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY), and the evoked cardiovascular response was observed. Unlike the injection areas, the threshold dose of one peptide for the cardiovascular response was similar, but the threshold dose differed from peptide to peptide. The threshold dose was lower for AII (0.15-0.29 pmol), in-between for ANP (0.9-1.5 pmol) and higher for AVP (14-30 pmol). No significant difference in the threshold dose was observed between SHR and WKY, suggesting that hypertension in SHR may not be due to the abnormal sensitivity to the three peptides of the vasomotor control neurons in the AP, NTS, and RVLM. The structural basis of the results of the microstimulation experiment was supported by the double-labeling study. The NTS neurons were innervated by (1) the AII-immunoreactive (ir) neurons in both sides of the lateral hypothalamic area (LH), the RVLM and the caudal ventrolateral medulla, and (2) the ANP-ir neurons in both sides of the paraventricular nucleus (Pa) and the LH. The RVLM neurons were innervated by (1) the AII-ir neurons in both sides of the LH and ipsilateral side of the lateral parabrachial nucleus (Pbl) and (2) the ANP-ir neurons in the ipsilateral Pbl. There was no evidence that the AVP-ir neurons in the Pa and the supraoptic nucleus innervate the NTS and the RVLM neurons, or that the AII, ANP or AVP-ir neurons innervate the AP neurons. This study suggests that in common with SHR and WKY rats AII and ANP may influence both the NTS and RVLM not by the humoral pathway but by the neural pathway, and AVP may not influence the three vasomotor control areas by the neural pathway.
为研究体液控制肽对延髓血管舒缩控制神经元的影响，将血管紧张素II（AII）、精氨酸加压素（AVP）和心房利钠肽（ANP）微量注射到自发性高血压大鼠（SHR）和正常血压的Wistar Kyoto大鼠（WKY）的三个血管舒缩控制区域，即最后区（AP）、孤束核（NTS）和延髓头端腹外侧区（RVLM），并观察诱发的心血管反应。与注射区域不同，一种肽引起心血管反应的阈剂量相似，但不同肽之间的阈剂量有所不同。AII的阈剂量较低（0.15 - 0.29皮摩尔），ANP的阈剂量居中（0.9 - 1.5皮摩尔），AVP的阈剂量较高（14 - 30皮摩尔）。在SHR和WKY之间未观察到阈剂量的显著差异，这表明SHR的高血压可能并非由于AP、NTS和RVLM中血管舒缩控制神经元对这三种肽的异常敏感性所致。微刺激实验结果的结构基础得到了双重标记研究的支持。NTS神经元接受以下神经支配：（1）来自双侧下丘脑外侧区（LH）、RVLM和延髓尾端腹外侧区的AII免疫反应性（ir）神经元，以及（2）来自双侧室旁核（Pa）和LH的ANP - ir神经元。RVLM神经元接受以下神经支配：（1）来自LH双侧和同侧臂旁外侧核（Pbl）的AII - ir神经元，以及（2）来自同侧Pbl的ANP - ir神经元。没有证据表明Pa和视上核中的AVP - ir神经元支配NTS和RVLM神经元，或者AII、ANP或AVP - ir神经元支配AP神经元。本研究表明，与SHR和WKY大鼠一样，AII和ANP可能并非通过体液途径而是通过神经途径影响NTS和RVLM，并且AVP可能并非通过神经途径影响这三个血管舒缩控制区域。
