Judy W V, Watanabe A M, Henry D P, Besch H R, Murphy W R, Hockel G M
Circ Res. 1976 Jun;38(6 Suppl 2):21-9. doi: 10.1161/01.res.38.6.21.
Sympathetic nerve activity (SNA) and high pressure baroreceptor regulation of SNA were studied in the Okamoto strain of spontaneously hypertensive rat (SHR). Mean arterial pressure (MAP) and SNA were not significantly affected by anesthesia with low doses of pentobarbital (20-25 mg/kg). Thus, most of these studies were performed in anesthetized rats. SNA in visceral sympathetic nerves increased rapidly with age up to 24 weeks and slowly thereafter. MAP increased with SNA, following the same time course. Both SNA and MAP in SHR were significantly greater than that found in normotensive Wistar control rats of comparable ages. Abolition of ganglionic transmission with hexamethonium in both SHR and normotensive controls reduced postganglionic SNA and MAP to comparable levels. In SHR less than 16 weeks old, increased baroreceptor stimulation effectively inhibited SNA with the same sensitivity as found in Wistar control rats. However, older SHR appeared to lose their ability to completely inhibit SNA during induced hypertension, whereas in Wistar control rats as old as 52 weeks, elevation of blood pressure to 165.3 +/- 2.3 mm Hg completely suppressed SNA. These results suggest that SNA may play an important role in the development and maintenance of hypertension in SHR, and that central sympathetic centers, uninhibited by baroreceptor afferents, become active during the development of hypertension in the SHR.
在冈本自发性高血压大鼠（SHR）品系中研究了交感神经活动（SNA）以及SNA的高压压力感受器调节。低剂量戊巴比妥（20 - 25 mg/kg）麻醉对平均动脉压（MAP）和SNA无显著影响。因此，这些研究大多在麻醉大鼠中进行。内脏交感神经中的SNA在24周龄前随年龄迅速增加，之后增加缓慢。MAP随SNA增加，具有相同的时间进程。SHR中的SNA和MAP均显著高于同龄正常血压的Wistar对照大鼠。六甲铵消除SHR和正常血压对照大鼠的神经节传递后，节后SNA和MAP降至相当水平。在小于16周龄的SHR中，增加压力感受器刺激可有效抑制SNA，其敏感性与Wistar对照大鼠相同。然而，年龄较大的SHR在诱导高血压期间似乎失去了完全抑制SNA的能力，而在高达52周龄的Wistar对照大鼠中，血压升高至165.3±2.3 mmHg可完全抑制SNA。这些结果表明，SNA可能在SHR高血压的发生和维持中起重要作用，并且在SHR高血压发生过程中，不受压力感受器传入抑制的中枢交感神经中枢变得活跃。
