Figure 5.

In the lung, high-fat diet (HFD)-induced airway hyperresponsiveness was reduced by metformin, but not by switching to a low-fat diet (LFD). Bronchoconstriction induced by electrical stimulation of both vagus nerves was potentiated by a high-fat diet (A).Metformin blocked the HFD-induced potentiation (B). However, switching the diet from high-fat to low-fat (HFD 5wk/LFD 5wk) did not reverse potentiation of vagally induced bronchoconstriction in rats on a high-fat diet (HFD 10wk; C). Bronchoconstriction induced by inhaled methacholine in vagotomized rats (D–F) was dose-dependent but was not significantly different among groups of rats, regardless of diet or treatment. n = 5–8 rats/group. Data are presented as means ± SE. *P < 0.05.