Stress ( IF 2.3 ) Pub Date : 2020-07-02 , DOI: 10.1080/10253890.2020.1777971 Martin Vodička 1 , Anna Vavřínová 1 , Anna Mikulecká 1 , Josef Zicha 1 , Michal Behuliak 1
Abstract
Fischer 344 (F344) rats are characterized by the hyper-reactive hypothalamic-pituitary-adrenal axis to stressful stimuli, while Lewis (LEW) rats are considered to be hypo-reactive. We studied stress-induced cardiovascular, neuroendocrine, and behavioral responses of adult male F344 and LEW rats subjected to the single (120 min) or the repeated restraint stress (daily 120 min for 1 week). Mean arterial pressure (MAP) and heart rate (HR) were measured in the restrained rats (n = 7–8 for each group) via a catheter inserted into the femoral artery. Baroreceptor sensitivity was evaluated using NO donor sodium nitroprusside and α1-adrenoceptor agonist phenylephrine. The plasma levels of adrenocorticotropic hormone (ACTH), corticosterone, aldosterone, and adrenaline were determined before and during the restraint. Exploratory behavior was tested in open field test. F344 rats exerted the augmented stress-induced increase in plasma ACTH, corticosterone, and adrenaline as well as the impaired endocrine adaptation to the repeated stress compared to LEW rats. F344 rats exhibited higher MAP than LEW rats during single and repeated restraint. Moreover, repeatedly restrained F344 showed elevated HR and diminished baroreflex sensitivity. F344 and LEW rats exhibited similar total locomotor activity and the time spent in the center of open field arena, both parameters being decreased by the repeated restraint. The detailed analysis revealed altered pattern of locomotor behavior in F344 rats subjected to repeated restraint. In conclusion, F344 rats showed the impaired endocrine adaptation that resulted in allostatic overload, which might contribute to the impaired cardiovascular and behavioral adaptation to chronic stress observed in this strain.
- Lay summary
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F344 rats, characterized by HPA axis hyper-reactivity, exhibited higher blood pressure during restraint than LEW rats. Moreover, repeatedly restrained F344 rats showed elevated heart rate and impaired baroreflex sensitivity. It can be concluded that a poor adaptation to the repeated stress in F344 rats is not only limited to the neuroendocrine response but also has important cardiovascular consequences.
中文翻译:
Fischer 344大鼠中HPA轴的过度反应与心血管和行为适应能力下降有关,以抑制重复性约束压力。
摘要
Fischer 344(F344)大鼠的特征是对应激刺激的下丘脑-垂体-肾上腺轴过度反应,而Lewis(LEW)大鼠被认为反应低下。我们研究了成年雄性F344和LEW大鼠承受单次(120分钟)或反复约束压力(每天120分钟,持续1周)的应激诱导的心血管,神经内分泌和行为反应。 通过插入股动脉的导管在受限大鼠(每组n = 7-8 )中测量平均动脉压(MAP)和心率(HR)。使用硝普钠NO供体钠压力感受器敏感度评价和α 1-肾上腺素受体激动剂去氧肾上腺素。在抑制之前和抑制期间测定血浆促肾上腺皮质激素(ACTH),皮质酮,醛固酮和肾上腺素的水平。探索性行为在露天测试中进行了测试。与LEW大鼠相比,F344大鼠在应激下导致血浆ACTH,皮质酮和肾上腺素的升高,并且内分泌对反复应激的适应性受损。F344大鼠表现出更高的MAP比LEW大鼠单和重复约束。此外,反复受约束的F344显示HR升高和压力反射敏感性降低。F344和LEW大鼠表现出相似的总运动能力和在旷野竞技场中心花费的时间,这两个参数由于反复约束而降低。详细的分析显示,在反复约束下,F344大鼠的运动行为发生了改变。总之,F344大鼠的内分泌适应能力受损,导致同种异体过载,这可能导致该菌株对慢性应激的心血管和行为适应能力受损。
- 放置摘要
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以HPA轴超反应为特征的F344大鼠在约束期间的血压高于LEW大鼠。此外,反复受约束的F344大鼠表现出较高的心率和受损的压力反射敏感性。可以得出结论,对F344大鼠反复应激的不良适应性不仅限于神经内分泌反应,而且还具有重要的心血管后果。