Department of Drugs and Pharmaceutics, Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Rodovia Araraquara KM 01 (Campus Universitário), Araraquara, SP, 14800-903, Brazil.
Joint UFSCar-UNESP Graduate Program in Physiological Sciences, São Carlos, SP, Brazil.
Pflugers Arch. 2020 Oct;472(10):1495-1506. doi: 10.1007/s00424-020-02451-9. Epub 2020 Aug 22.
We investigated the spontaneous recovery, time course, and the influence of the time of day on the habituation of the cardiovascular responses with repeated exposure to restraint stress in male rats. Habituation of the corticosterone response to repeated restraint stress was also evaluated. The circulating corticosterone response decreased during both the stress and recovery periods of the tenth session of restraint. Habituation of the cardiovascular responses was identified as a faster return to baseline values of the heart rate (HR) and blood pressure (BP) during the recovery period of the tenth session of restraint. Habituation of the HR and BP was still observed after 10 days of discontinuation of the repeated exposure to restraint stress. However, spontaneous recovery of habituated responses was observed 20 days after the final restraint stress session. Time course analysis revealed decreased HR response during the recovery period of the third restraint session, without further reduction on the fifth, seventh, and tenth sessions. Decreased BP response was identified on the third and fifth sessions, whereas reduced tail skin temperature response was observed only on the fifth and seventh sessions. Regarding the time of day, habituation of the tachycardiac response was identified at the tenth session when repeated restraint stress was performed in the morning and night periods, but not in the afternoon. These findings provided evidence of spontaneous recovery of the habituation of cardiovascular responses to repeated restraint stress. Moreover, cardiovascular habituation was dependent on the number of trials and time of day.
我们研究了雄性大鼠反复暴露于束缚应激下心血管反应的自发恢复、时程以及白天时间对其习惯化的影响。还评估了重复束缚应激下皮质酮反应的习惯化。在第十次束缚应激的应激和恢复期间，循环皮质酮反应降低。心血管反应的习惯化表现为在第十次束缚应激恢复期间，心率（HR）和血压（BP）更快地恢复到基线值。在停止重复暴露于束缚应激 10 天后，仍然观察到 HR 和 BP 的习惯化。然而，在最后一次束缚应激后 20 天观察到习惯化反应的自发恢复。时程分析显示，在第三次束缚恢复期间 HR 反应降低，而在第五、第七和第十次束缚中没有进一步降低。在第三次和第五次束缚中观察到 BP 反应降低，而在第五和第七次束缚中仅观察到尾巴皮肤温度反应降低。关于时间，当在早晨和晚上重复进行束缚应激时，在第十次束缚应激时观察到心动过速反应的习惯化，但在下午则没有。这些发现为重复束缚应激引起的心血管反应习惯化的自发恢复提供了证据。此外，心血管习惯化依赖于试验次数和时间。
