Dominant Mice are Protected from the Metabolic Alterations Induced by High Fat Diet Feeding.

Obesity is a metabolic disorder, leading to an increased risk for several morbidities, such as diabetes and fatty liver diseases. In addition, epidemiological data demonstrates a bidirectional association between depression and obesity, however the mechanisms underlying this association were not fully elucidated yet.

The aim of this study is to explore whether dominant or submissive behavioral phenotype is associated with a different susceptibility to obesity and comorbidities in mice.

Research design: The study is performed in a selectively bred Dominant (Dom) and Submissive (Sub) mice. Mice were given high fat diet (HFD) or standard diet (STD) for 8 weeks, followed by physiological, histological and behavioral analyses.

Results: HFD-feeding induced an elevation in fasting blood glucose and a severe glucose intolerance in Sub, while Dom mice were almost unaffected. Insulin sensitivity was disturbed in HFD-fed Sub, while Dom mice had normal response to insulin. Histochemical analysis revealed pancreatic islets hypertrophy and pancreatic steatosis in Sub mice, with a lower severity of such pathologies in Dom mice. In addition, Dom were protected from HFD-induced hepatic steatosis, which was observed in Sub mice.

In conclusion, this study clearly suggests that molecular mechanisms underlying social dominance may be involved in protective effects again HFD-induced pathologies.