Challa Siva Reddy, Fornal Casimir A, Wang Billy C, Boyineni Jerusha, DeVera Roberto E, Unnam Pavani, Song Yajing, Soares Marcelo Bento, Malchenko Sergey, Gyarmati Peter, Veeravalli Krishna Kumar
Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine Peoria, Peoria, IL, USA.
Department of Pharmacology, KVSR Siddhartha College of Pharmaceutical Sciences, Vijayawada, AP, India.
Chronic Stress (Thousand Oaks). 2023 Oct 17;7:24705470231207010. doi: 10.1177/24705470231207010. eCollection 2023 Jan-Dec.
Social isolation (SI) and loneliness are major adult and adolescent health concerns, particularly in the coronavirus disease 2019 (COVID-19) era. Recent prospective cohort studies indicate that older women who experienced both SI and loneliness had a significantly higher risk of cardiovascular disease (CVD). Hypertension, a well-established risk factor for CVD, is more prevalent in elderly women than men. Furthermore, a lack of social relationships is strongly associated with an increased risk of hypertension in middle-aged and elderly women compared to men. Although this has not been extensively studied, adolescents and young adults who experience loneliness or SI may also be at risk for CVD and depression. The purpose of this study was to examine the effect of SI on blood pressure and depression-like behavior in young male and female mice. Weaned C57BL/6 mice were randomly assigned ( = 6/group/sex) to either group housing (GH) or SI. Animals in the SI group were housed in individual cages for 8 weeks with no view of other animals. The cages were kept in ventilated racks to prevent pheromone exposure and socially isolated animals had no cage enrichment. SI increased systolic, diastolic, and mean arterial blood pressure in females and elevated heart rate in both sexes. Body weight gain was dramatically increased in socially isolated females but tended to decrease in socially isolated males. In the forced swim test, which detects depression-like behavior, there was no difference between groups in total immobility time. The latency to immobility, however, was significantly decreased in socially isolated females. Serum concentrations of corticosterone and metanephrine did not differ between socially isolated and group-housed females, but corticosterone levels were significantly reduced in socially isolated males. Our results indicate that 8 weeks of SI leads to significant changes in blood pressure and heart rate and mild changes in depression-like behavior in young mice, with females affected more than males.
社交隔离（SI）和孤独感是成年人及青少年健康的主要问题，尤其是在2019冠状病毒病（COVID-19）时代。最近的前瞻性队列研究表明，经历过社交隔离和孤独感的老年女性患心血管疾病（CVD）的风险显著更高。高血压是一种公认的心血管疾病风险因素，在老年女性中比男性更为普遍。此外，与男性相比，缺乏社交关系与中老年女性患高血压的风险增加密切相关。尽管这方面尚未得到广泛研究，但经历孤独感或社交隔离的青少年和年轻人也可能有患心血管疾病和抑郁症的风险。本研究的目的是研究社交隔离对年轻雄性和雌性小鼠血压及类似抑郁行为的影响。将断奶的C57BL/6小鼠随机分配（每组/性别 = 6只）至群居（GH）或社交隔离组。社交隔离组的动物被单独饲养在笼子里8周，看不到其他动物。笼子放置在通风架上以防止接触信息素，且社交隔离的动物没有笼子装饰。社交隔离使雌性小鼠的收缩压、舒张压和平均动脉血压升高，使两性的心率升高。社交隔离的雌性小鼠体重显著增加，而社交隔离的雄性小鼠体重则有下降趋势。在检测类似抑郁行为的强迫游泳试验中，两组在总不动时间上没有差异。然而，社交隔离的雌性小鼠不动潜伏期显著缩短。社交隔离和群居的雌性小鼠血清皮质酮和间甲肾上腺素浓度没有差异，但社交隔离的雄性小鼠皮质酮水平显著降低。我们的结果表明，8周的社交隔离会导致年轻小鼠血压和心率发生显著变化，以及类似抑郁行为出现轻微变化，雌性受影响程度大于雄性。
