Kim J H, Snider T, Abel M, Zemel M B
Department of Nutrition, University of Tennessee, Knoxville 37996-1900.
J Nutr. 1994 May;124(5):713-6. doi: 10.1093/jn/124.5.713.
Hypertension in insulin resistant states is, in part, salt and volume dependent. The Zucker obese rat, a model of hypertension associated with insulin resistance, has been shown to exhibit a pressor response to a fourfold increase in NaCl intake, from 1 to 4 g/100 g. However, it is not clear if blood pressure is responsive to less severe manipulations, or if a NaCl restricted diet results in a depressor effect comparable to the pressor effect of adding supplementary NaCl to a normal diet. Consequently, we have determined the effects of NaCl restriction on blood pressure in Zucker lean and obese rats. Twenty-four 6-wk-old female Zucker lean and obese rats were randomly assigned to either a normal diet (1 g/100 g NaCl) or a NaCl restricted (0.26 g/100 g) diet for 4 wk. Direct intra-arterial blood pressure was then measured in conscious, unrestrained animals via a femoral cannula connected to a low volume pressure transducer and physiological recorder. Animals fed both diets grew normally, and there was no effect of diet on either food consumption or growth rate. Blood pressure was significantly higher in the obese than the lean rats. However, reducing NaCl intake had no effect on blood pressure in either group. Heart rate was not significantly different among the 4 groups. These data demonstrate that moderate reductions in dietary NaCl intake are without effect on blood pressure in Zucker obese rats despite their pressor response to large quantities of NaCl.
胰岛素抵抗状态下的高血压部分取决于盐和血容量。Zucker肥胖大鼠是一种与胰岛素抵抗相关的高血压模型，已证明其对NaCl摄入量从1 g/100 g增加至4 g/100 g（增加四倍）会产生升压反应。然而，尚不清楚血压是否对不太严重的操作有反应，或者NaCl限制饮食是否会产生与在正常饮食中添加补充NaCl的升压作用相当的降压作用。因此，我们确定了NaCl限制对Zucker瘦鼠和肥胖大鼠血压的影响。将24只6周龄的雌性Zucker瘦鼠和肥胖大鼠随机分为正常饮食组（1 g/100 g NaCl）或NaCl限制饮食组（0.26 g/100 g），持续4周。然后通过连接到低容量压力传感器和生理记录仪的股动脉插管，在清醒、不受约束的动物中测量直接动脉内血压。两种饮食喂养的动物均正常生长，饮食对食物消耗或生长速率均无影响。肥胖大鼠的血压显著高于瘦大鼠。然而，降低NaCl摄入量对两组的血压均无影响。4组之间的心率无显著差异。这些数据表明，尽管Zucker肥胖大鼠对大量NaCl有升压反应，但适度减少饮食中NaCl摄入量对其血压没有影响。
