Lawler J E, Abel M M, Naylor S K
Physiology Program, University of Tennessee, Knoxville 37996-0900.
Physiol Behav. 1993 Jan;53(1):97-102. doi: 10.1016/0031-9384(93)90016-9.
The SHR shows chronic elevations in blood pressure in response to stress or a high salt diet, at least in some studies. Stress and salt have also been combined in studies in the SHR. Tonic levels of blood pressure are not clearly elevated by superimposing acute stress on top of a chronic high salt diet. The BHR is a new model with lower resting blood pressure and marked sensitivity to environmental stressors such as stress and dietary salt intake. In the present study, SHR, BHR, or WKY were placed on a normal or high salt (8% in chow) diet. During the 8th week of the appropriate diet, blood pressure and heart rate were monitored during rest and footshock stress. Salt elevated the resting blood pressure in all three strains, but only marginally in the WKY. Stress did not further elevate the effect seen with salt, although it had a differential effect on heart rate in the three strains. In SHR, the salt group had a higher heart rate, although in BHR it was no different, and in WKY it was lower, than that seen in same-strain normal diet groups. The results are discussed in terms of the ability of the combination of stress and chronic high salt intake to alter baroreflex function in SHR, although only marginally affecting it in BHR. WKY, on the other hand, do not show evidence of altered baroreflex function when an acute stressor is superimposed on a high-salt diet.
至少在一些研究中，自发性高血压大鼠（SHR）在应激或高盐饮食时会出现慢性血压升高。在对SHR的研究中，也有将应激和盐结合起来进行的。在慢性高盐饮食基础上叠加急性应激，血压的静息水平并没有明显升高。血压反应性高的大鼠（BHR）是一种新的模型，其静息血压较低，对环境应激源（如应激和饮食中的盐摄入量）具有明显的敏感性。在本研究中，将SHR、BHR或WKY大鼠置于正常或高盐（饲料中含8%）饮食中。在适当饮食的第8周，在休息和足部电击应激期间监测血压和心率。盐使所有三个品系的静息血压升高，但在WKY大鼠中仅略有升高。应激并没有进一步增强盐的作用，尽管它对三个品系的心率有不同的影响。在SHR中，盐组的心率较高，而在BHR中与正常饮食组没有差异，在WKY中则低于同品系正常饮食组。本文讨论了应激和慢性高盐摄入联合作用改变SHR压力反射功能的能力，尽管对BHR的影响很小。另一方面，当在高盐饮食基础上叠加急性应激源时，WKY大鼠没有显示出压力反射功能改变的证据。
