Sex Differences in the Adverse Electromechanical Remodeling of the Heart after Repeated Witness Stress in Adult Rats: Relationship with a Specific miRNA Signature.

Objective: Sex disparities in the association between psychosocial stress and cardiovascular risk have been reported, yet the extent to which social stress impacts cardiovascular function in a sex-specific manner remains unclear. The objectives of this study were to investigate sex differences in the electromechanical remodeling of the heart of socially stressed rats, and to explore potential epigenetic mechanisms (cardiac microRNAs).

Methods: Adult wild-type Groningen rats of both sexes vicariously experienced the social defeat bout between two males for nine consecutive days ("witness stress" (WS) paradigm) or were exposed to a control condition (n=8/sex/group).

Repeated witness social stress causes cardiomyocyte contractile impairment and intracellular Ca derangement in female rats.

The impact of psychosocial stressors on cardiovascular health in women is of growing interest in both the popular and scientific literature. Rodent models are useful for providing direct experimental evidence of the adverse cardiovascular consequences of psychosocial stressors, yet studies in females are scarce. Here, we investigated the effects of repeated exposure to witness social defeat stress (WS) on cardiomyocyte contractile function and intracellular Ca homeostasis in young adult wild-type Groningen female rats.