Substance P antagonist improves both obesity and asthma in a mouse model

Background Evidence suggests a causal relationship between obesity and asthma; however, the underlying mechanisms remain unknown. Substance P (SP), involved in neurogenic inflammation by acting through its receptor NK1‐R, seems to participate in obese–asthma phenotype in mice. Objectives To evaluate the effect of a selective substance P receptor antagonist on a mouse model of diet‐induced obesity and asthma. Methods Diet‐induced obese Balb/c mice were sensitized and challenged with ovalbumin (OVA) and treated with a selective NK1‐R antagonist or placebo. Serum glucose, insulin, IL‐6, resistin, and OVA‐specific IgE levels were quantified. A score for peribronchial inflammation in lung histology was used. Cells were counted in bronchoalveolar lavage fluid. Adipocyte sizes were measured. Results Ovalbumin‐obese mice treated with NK1‐R antagonist had lower weight (P = 0.0002), reduced daily food intake (P = 0.0021), reduced daily energy intake (P = 0.0021), reduced surface adipocyte areas (P