Oxytocin administration rescues the negative impacts of social isolation on wound healing in mice

Abstract

In humans and animals, social isolation leads to worsened health outcomes in many disease areas, including wound healing. Oxytocin, a prosocial hormone with anti-inflammatory properties, has been strongly implicated in the salutary benefits of social relationships. Oxytocin administration can mitigate the negative effects of social isolation on health outcomes, as demonstrated in rat and hamster wound healing models. However, little research has been conducted with mice, which are more common laboratory animal models, and which have markedly different social structures from these other rodent species. Moreover, the effects of social isolation and oxytocin administration on wound healing have not been investigated in mice within the same experiment, nor have they been compared between males and females. Here, we housed male and female C57BL/6 mice (n = 40) in social isolation or same-sex pairs. Mice received a subcutaneous biopsy punch wound and were subsequently administered IP oxytocin or placebo daily for 14 days. Socially isolated mice administered oxytocin, and pair-housed mice administered either oxytocin or placebo, showed a significantly faster decrease in wound area and more collagen fiber variance (i.e., less scar tissue) compared to socially isolated mice administered placebo. No sex differences were observed in any outcome measure. Thus, social housing and oxytocin administration each non-additively reduce the negative effects of social isolation on wound healing in mice. Oxytocin administration may be a promising pharmacological strategy by which to improve post-surgical healing in animals and humans, especially in those where limited social contact is necessary or in those with sparse social networks.