Lawler J E, Naylor S K, Abel M M
Physiology Program, University of Tennessee, Knoxville 37996-0900.
Physiol Behav. 1993 Aug;54(2):369-74. doi: 10.1016/0031-9384(93)90125-y.
Because animals prefer predictable over unpredictable shock, it was hypothesized that rats receiving unpredictable foot shock would show greater phasic blood pressure responses. Furthermore, because some studies utilizing human subjects suggest that blood pressure responses to stress are greater in those with a positive family history of hypertension, the current study examined the phasic blood pressure response to alterations in foot shock predictability in rats with either zero, one, or two hypertensive parents. Predictability was manipulated by altering the percentage of trials during which foot shock was associated with a tone, while at the same time keeping the total number of foot shocks equal in all groups. During the first few trials, the most unpredictable foot shock was associated with higher blood pressure, a trend that was significant for the borderline hypertensive rat (BHR) and marginal for the spontaneously hypertensive rat (SHR). It was also noted that, over the 28 foot-shock trials comprising the stress session, habituation of the blood pressure response was obtained for the most unpredictable shock group. Again, this occurred in those rats with a genetic history of hypertension (SHR and BHR). The results are discussed in relation to studies of stress and blood pressure reactivity in humans with a positive family history of hypertension.
由于动物更喜欢可预测的电击而非不可预测的电击，因此推测接受不可预测足部电击的大鼠会表现出更大的相位血压反应。此外，由于一些针对人类受试者的研究表明，有高血压家族史的人对应激的血压反应更大，当前研究考察了具有零个、一个或两个高血压亲本的大鼠对足部电击可预测性改变的相位血压反应。通过改变足部电击与音调相关联的试验百分比来操纵可预测性，同时保持所有组的足部电击总数相等。在最初的几次试验中，最不可预测的足部电击与较高的血压相关，这一趋势在临界高血压大鼠（BHR）中显著，在自发性高血压大鼠（SHR）中不明显。还注意到，在包括应激阶段的28次足部电击试验中，最不可预测电击组的血压反应出现了习惯化。同样，这发生在具有高血压遗传史的大鼠（SHR和BHR）中。结合对有高血压家族史的人类应激和血压反应性的研究对结果进行了讨论。
