Duarte Josiane O, Planeta Cleopatra S, Crestani Carlos C
Laboratory of Pharmacology, Department of Drugs and Medicines, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil.
Laboratory of Pharmacology, Department of Drugs and Medicines, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil.
Life Sci. 2023 Apr 1;318:121473. doi: 10.1016/j.lfs.2023.121473. Epub 2023 Feb 4.
This study investigated the influence of exposure to stress during adolescence in autonomic, cardiovascular, neuroendocrine and somatic changes evoked by chronic stress in adult rats.
Animals were subjected to a 10-days protocol of repeated restraint stress (RRS, habituating) or chronic variable stress (CVS, non-habituating) during adolescence, adulthood, or repeated exposure to either RRS or CVS in adolescence and adulthood (adolescence+adulthood group). The trials to measure autonomic, cardiovascular, neuroendocrine and somatic changes in all experimental groups were performed in adulthood.
CVS increased basal circulating corticosterone levels and caused adrenal hypertrophy in the adolescence+adulthood group, an effect not identified in animals subjected to this stressor only in adulthood or adolescence. CVS also caused a sympathetically-mediated resting tachycardia in the adulthood group. This effect of CVS was not identified in the adolescence+adulthood group once the increased cardiac sympathetic activity was buffered by a decrease in intrinsic heart rate in these animals. Moreover, the impairment in baroreflex function observed in the adulthood group subjected to CVS was shifted to an improvement in animals subjected to repeated exposure to this stressor during adolescence and adulthood. The RRS in the adolescence+adulthood group caused a sympathetically-mediated resting tachycardia, which was not observed in the adulthood group.
Our findings suggest that enduring effects of adverse events during adolescence included a vulnerability to neuroendocrine changes and a resilience to autonomic and cardiovascular dysfunctions caused by the CVS. Furthermore, results of RRS indicated a vulnerability to cardiovascular and autonomic changes evoked by homotypic stressors.
本研究调查了青春期暴露于应激对成年大鼠慢性应激诱发的自主神经、心血管、神经内分泌和躯体变化的影响。
动物在青春期、成年期接受为期10天的重复束缚应激（RRS，适应性）或慢性可变应激（CVS，非适应性）实验方案，或在青春期和成年期重复暴露于RRS或CVS（青春期+成年期组）。所有实验组测量自主神经、心血管、神经内分泌和躯体变化的实验均在成年期进行。
CVS增加了青春期+成年期组的基础循环皮质酮水平并导致肾上腺肥大，仅在成年期或青春期接受此应激源的动物中未发现这种效应。CVS还在成年期组中引起了交感神经介导的静息性心动过速。一旦这些动物的固有心率降低缓冲了心脏交感神经活动的增加，CVS的这种效应在青春期+成年期组中未被发现。此外，成年期接受CVS的组中观察到的压力反射功能损害在青春期和成年期反复暴露于该应激源的动物中转变为改善。青春期+成年期组中的RRS引起了交感神经介导的静息性心动过速，成年期组中未观察到这种情况。
我们的研究结果表明，青春期不良事件的持久影响包括对神经内分泌变化的易感性以及对CVS引起的自主神经和心血管功能障碍的恢复力。此外，RRS的结果表明对同型应激源诱发的心血管和自主神经变化具有易感性。
