Hsu C H, Slavicek J H, Kurtz T W
Am J Physiol. 1982 Jun;242(6):H961-6. doi: 10.1152/ajpheart.1982.242.6.H961.
Renal hemodynamics were studied during different stages of development of hypertension in unanesthetized spontaneously hypertensive rats (SHR). In SHR at 4 wks of age mean arterial pressure (MAP) was higher than in age-matched Wistar Kyoto rats (WKY); however, renal blood flow (RBF) and renal vascular resistance (RVR) were not different between these two groups. Mean values of RVR and MAP in 8- and 12-wk-old SHR were significantly greater than those of age-matched WKY. Both RBF of 8- and 12-wk-old SHR were significantly lower than the corresponding values of WKY. Afferent arteriolar diameter (AAD) was measured with a microsphere method. AAD was not different between 4-wk-old SHR and WKY; however, the AAD of 8-wk-old (16.3 +/- 0.23 micrometers, n = 5) and 12-wk-old (17.4 +/- 0.48, n = 5) SHR were significantly smaller than those of respective control WKY (17.3 +/- 0.34, n = 4, P less than 0.05; 19.3 +/- 0.12, n = 5, P less than 0.01). Calculated preglomerular (Rpre) and postglomerular resistances (Rpost) of 12-wk-old SHR were increased 96 and 129% when compared with respective segmental resistances of the control WKY. The decrease in AAD of 12-wk-old SHR was sufficient to account for a 33% increase in Rpre. After the rats were treated with hydralazine (0.5 mg/kg iv), MAP, RBF, and RVR of SHR were not different from the control WKY values. Rpre and Rpost of SHR were substantially decreased; however, vasodilation occurred at vessels proximal and distal to the afferent arteriole because AAD was not altered. Our results indicate that increased RVR in SHR involves increases in Rpre and Rpost.
在未麻醉的自发性高血压大鼠（SHR）高血压发展的不同阶段对肾血流动力学进行了研究。4周龄的SHR平均动脉压（MAP）高于年龄匹配的Wistar Kyoto大鼠（WKY）；然而，这两组之间的肾血流量（RBF）和肾血管阻力（RVR）并无差异。8周龄和12周龄SHR的RVR和MAP平均值显著高于年龄匹配的WKY。8周龄和12周龄SHR的RBF均显著低于WKY的相应值。采用微球法测量入球小动脉直径（AAD）。4周龄的SHR和WKY之间的AAD无差异；然而，8周龄（16.3±0.23微米，n = 5）和12周龄（17.4±0.48，n = 5）SHR的AAD显著小于各自的对照WKY（17.3±0.34，n = 4，P<0.05；19.3±0.12，n = 5，P<0.01）。与对照WKY的相应节段阻力相比，12周龄SHR的计算肾小球前阻力（Rpre）和肾小球后阻力（Rpost）分别增加了96%和129%。12周龄SHR的AAD降低足以解释Rpre增加33%。大鼠静脉注射肼屈嗪（0.5 mg/kg）后，SHR的MAP、RBF和RVR与对照WKY值无差异。SHR的Rpre和Rpost显著降低；然而，由于AAD未改变，入球小动脉近端和远端的血管发生了血管舒张。我们的结果表明，SHR中RVR的增加涉及Rpre和Rpost的增加。
