Duarte Josiane O, Cruz Fábio C, Leão Rodrigo M, Planeta Cleopatra S, Crestani Carlos C
From the Laboratory of Pharmacology (Duarte, Planeta, Crestani), School of Pharmaceutical Sciences, University of Estadual Paulista-UNESP, Araraquara, SP, Brazil; Joint UFSCar-UNESP Graduate Program in Physiological Sciences (Duarte, Planeta, Crestani), São Carlos, SP, Brazil; and Behavioral Neuroscience Branch (Cruz, Leão), Intramural Research Program, National Institute on Drug Abuse, US National Institutes of Health, Department of Health and Human Services, Baltimore, Maryland.
Psychosom Med. 2015 Feb-Mar;77(2):186-99. doi: 10.1097/PSY.0000000000000141.
This study investigated the physiological and somatic changes evoked by daily exposure to the same type of stressor (homotypic) or different aversive stressor stimuli (heterotypic) in adolescent and adult rats, with a focus on cardiovascular function. The long-term effects of stress exposure during adolescence were also investigated longitudinally.
Male Wistar rats were exposed to repeated restraint stress (RRS, homotypic) or chronic variable stress (CVS, heterotypic).
Adrenal hypertrophy, thymus involution, and elevated plasma glucocorticoid were observed only in adolescent animals, whereas reduction in body weight was caused by both stress regimens in adults. CVS increased mean arterial pressure (adolescent: p = .001; adult: p = .005) and heart rate (HR; adolescent: p = .020; adult: p = .011) regardless of the age, whereas RRS increased blood pressure selectively in adults (p = .001). Rest tachycardia evoked by CVS was associated with increased cardiac sympathetic activity in adults, whereas a decreased cardiac parasympathetic activity was observed in adolescent animals. Changes in cardiovascular function and cardiac autonomic activity evoked by both CVS and RRS were followed by alterations in baroreflex activity and vascular reactivity to vasoconstrictor and vasodilator agents in adolescent adult animals. Except for the circulating glucocorticoid change, all alterations observed during adolescence were reversed in adulthood.
These findings suggest a stress vulnerability of adolescents to somatic and neuroendocrine effects regardless of stress regimen. Our results indicated an age-stress type-specific influence in stress-evoked cardiovascular/autonomic changes. Data suggest minimal consequences in adulthood of stress during adolescence.
本研究调查了青春期和成年大鼠每日暴露于同一类型应激源（同型）或不同厌恶应激源刺激（异型）所引起的生理和躯体变化，重点关注心血管功能。还纵向研究了青春期应激暴露的长期影响。
雄性Wistar大鼠暴露于重复束缚应激（RRS，同型）或慢性可变应激（CVS，异型）。
仅在青春期动物中观察到肾上腺肥大、胸腺萎缩和血浆糖皮质激素升高，而成年动物的两种应激方案均导致体重减轻。无论年龄大小，CVS均增加平均动脉压（青春期：p = 0.001；成年：p = 0.005）和心率（HR；青春期：p = 0.020；成年：p = 0.011），而RRS仅在成年动物中选择性地升高血压（p = 0.001）。CVS诱发的静息心动过速与成年动物心脏交感神经活动增加有关，而在青春期动物中观察到心脏副交感神经活动减少。CVS和RRS诱发的心血管功能和心脏自主神经活动变化之后，青春期和成年动物的压力反射活动以及血管对血管收缩剂和血管舒张剂的反应性也发生了改变。除了循环糖皮质激素变化外，青春期观察到的所有改变在成年期均得到逆转。
这些发现表明，无论应激方案如何，青少年对应激的躯体和神经内分泌影响具有易感性。我们的结果表明，在应激诱发的心血管/自主神经变化中存在年龄-应激类型特异性影响。数据表明青春期应激对成年期的影响最小。
