Meldrum M J, Glenton P
University of Florida, Department of Pharmacodynamics, JHMHC, Gainesville 32610.
Pharmacology. 1992;44(1):19-25. doi: 10.1159/000138869.
The potassium-induced release of 3H-norepinephrine (3H-NE) was examined in the rat caudal artery. A simple and reliable method was developed to examine stimulated neurotransmitter release from this highly innervated resistance vessel. The potassium-induced release of 3H-NE was dose- and calcium-dependent. Stimulated 3H-NE release was elevated in the spontaneously hypertensive (SHR) compared to age-matched Wistar-Kyoto (WKY) animals (p less than 0.05). However, in animals at 5-6 weeks of age, where the blood pressure was not different between the SHR and WKY, the stimulation-induced release of 3H-NE was also not significantly different. Low salt diets for 7 days significantly decreased the potassium-induced release of 3H-NE from both 10- to 11-week-old SHR and WKY animals. High salt diets did not significantly effect 3H-NE release, even though the high salt diets for 7 days significantly increased the blood pressure in the SHR. The results suggest that the caudal artery is a good model to study stimulation-induced transmitter release and that elevated 3H-NE release plays a role in the development of hypertension in the SHR. Low salt diets, which did not lower blood pressure, were shown to decrease 3H-NE release. High salt diets elevated the blood pressure in the SHR but had no significant effect on stimulated 3H-NE release.
在大鼠尾动脉中检测了钾诱导的3H-去甲肾上腺素（3H-NE）释放。开发了一种简单可靠的方法来检测这种高度神经支配的阻力血管中刺激后的神经递质释放。钾诱导的3H-NE释放呈剂量和钙依赖性。与年龄匹配的Wistar-Kyoto（WKY）动物相比，自发性高血压（SHR）大鼠中刺激后的3H-NE释放升高（p<0.05）。然而，在5至6周龄的动物中，SHR和WKY的血压并无差异，刺激诱导的3H-NE释放也无显著差异。7天的低盐饮食显著降低了10至11周龄SHR和WKY动物中钾诱导的3H-NE释放。高盐饮食对3H-NE释放无显著影响，尽管7天的高盐饮食显著提高了SHR的血压。结果表明，尾动脉是研究刺激诱导的递质释放的良好模型，且升高的3H-NE释放在SHR高血压的发展中起作用。未降低血压的低盐饮食可降低3H-NE释放。高盐饮食使SHR血压升高，但对刺激后的3H-NE释放无显著影响。
