Yamamoto R, Cline W H
J Pharmacol Exp Ther. 1987 Jun;241(3):826-32.
The release of endogenous norepinephrine (NE) from the mesenteric vasculature of the isolated mesentery of Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) was determined in response to periarterial nerve stimulation (PNS). PNS caused a frequency-dependent release of NE that did not differ in WKY and SHR preparations at 4 to 10 Hz but was significantly greater from SHR preparations at 12 and 14 Hz. When expressed as NE release/stimulus, release was significantly greater from SHR preparations only at 14 Hz. Mesenteric vascular perfusion-pressure responses to PNS were significantly greater in SHR than in WKY preparations at 6 to 14 Hz. Mesenteric vascular perfusion-pressure responses to exogenous NE were significantly greater in SHR than in WKY preparations at all doses tested. Treatment of mesenteric vascular preparations from WKY and SHR with cocaine at two concentrations plus corticosterone to inhibit neuronal and extraneuronal NE uptake, respectively, increased PNS-induced overflow of NE significantly. There was no difference in the NE release/stimulus in response to PNS between WKY and SHR preparations after either concentration of cocaine. The enhanced PNS responses in SHR at higher frequencies appear to be due in part to decreased NE uptake.
测定了Wistar Kyoto大鼠（WKY）和自发性高血压大鼠（SHR）离体肠系膜的肠系膜血管中内源性去甲肾上腺素（NE）的释放，以响应动脉周围神经刺激（PNS）。PNS引起NE的频率依赖性释放，在4至10Hz时，WKY和SHR制剂中的释放无差异，但在12和14Hz时，SHR制剂中的释放明显更大。当以NE释放/刺激表示时，仅在14Hz时，SHR制剂中的释放明显更大。在6至14Hz时，SHR对PNS的肠系膜血管灌注压反应明显大于WKY制剂。在所有测试剂量下，SHR对外源性NE的肠系膜血管灌注压反应明显大于WKY制剂。分别用两种浓度的可卡因加皮质酮处理WKY和SHR的肠系膜血管制剂，以抑制神经元和神经元外NE摄取，显著增加了PNS诱导的NE溢出。两种浓度的可卡因处理后，WKY和SHR制剂对PNS的NE释放/刺激无差异。SHR在较高频率下增强的PNS反应似乎部分归因于NE摄取减少。
