Figure 8. Early postnatal hyperalimentation pHA with early-onset obesity leads to greater airway resistance in murine model at postnatal day (P70) despite unaltered bronchial structure.

(A) Airway resistance (Res) after methacholine stimulation measured by direct plethysmography. Exposure of the mice at postnatal day 70 (P70) to PBS, followed by methacholine: 6.25 mg/ml and 12.5 mg/ml. Res was significantly increased after methacholine stimulation at P70 in the group with early postnatal hyperalimentation (pHA^mousegroup, n = 14 from 4 litters; open square) compared to the Ctrl (Ctrl, n = 9 from 6 litters; solid square); two-way ANOVA and Bonferroni posttest. (B) Minute volume and (C) tidal volume were measured during direct plethysmography; Mann Whitney test. pHA^mouse group: white bar; Ctrl: black bar; Mean ± SEM; Significance for each bar is indicated by p values. (D) Representative images of bronchi stained for α-smooth muscle actin (α-SMA) as an indicator of smooth muscle cells. Summary data for (E) measurement of the thickness of the bronchial smooth muscle layer (bSML) in the Ctrl-group and in the pHA^mouse-group at P70; (F) ratio of thickness of the bSML and bronchial wall thickness; (G) diameter of the lumen of the bronchi. Only bronchi with 100–200 μm diameter were used for assessment of bSML and bronchial wall thickness. pHA^mousegroup (n = 6 from 4 litterss): white bar; Ctrl (n = 6 from 5 litterss): black bar. Mean ± SEM; Mann Whitney test. *p < 0.05, **p < 0.01; n.s. = not significant.