Tsuda K, Masuyama Y
Department of Medicine, Wakayama Medical College, Japan.
Am J Hypertens. 1993 Jun;6(6 Pt 1):473-9. doi: 10.1093/ajh/6.6.473.
The present study was performed to investigate the effects of neurotensin on noradrenergic transmission in blood vessels of hypertension. In the perfused mesenteric vasculatures prepared from spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto (WKY) rats, we examined the influences of neurotensin on vascular responsiveness and norepinephrine release from adrenergic neurons. In studies with male standard Wistar rats, endogenous norepinephrine release during periarterial nerve stimulation was inhibited by neurotensin in a dose-dependent manner. Vasoconstrictor responses to electrical nerve stimulation were also inhibited by neurotensin. In SHR, the stimulation-evoked pressor responses and norepinephrine release were enhanced compared with WKY rats. The suppression of these responses by neurotensin was significantly less in SHR than in WKY rats. These results show that neurotensin could have a modulatory effect on noradrenergic activity and cause a decrease in stimulation-evoked norepinephrine release from vascular adrenergic neurons. The lesser reduction of pressor responses and norepinephrine release by neurotensin in SHR might suggest an insufficient regulation of vascular adrenergic transmission by the peptide hormone in hypertension.
本研究旨在探讨神经降压素对高血压血管中去甲肾上腺素能传递的影响。在从自发性高血压大鼠（SHR）和年龄匹配的Wistar-Kyoto（WKY）大鼠制备的灌注肠系膜血管系统中，我们研究了神经降压素对血管反应性和去甲肾上腺素能神经元释放去甲肾上腺素的影响。在雄性标准Wistar大鼠的研究中，神经降压素以剂量依赖性方式抑制动脉周围神经刺激期间内源性去甲肾上腺素的释放。神经降压素也抑制了对电神经刺激的血管收缩反应。与WKY大鼠相比，SHR中刺激诱发的升压反应和去甲肾上腺素释放增强。神经降压素对这些反应的抑制在SHR中明显少于WKY大鼠。这些结果表明，神经降压素可能对去甲肾上腺素能活性具有调节作用，并导致刺激诱发的血管去甲肾上腺素能神经元释放去甲肾上腺素减少。神经降压素在SHR中对升压反应和去甲肾上腺素释放的降低作用较小，这可能表明该肽类激素在高血压中对血管去甲肾上腺素能传递的调节不足。
