Figure 10

Airway contraction index is decreased in vitamin A deficient (VAD) rats. Airway contraction index (A/Ar, mean ± SEM, n = 9 rats for each retinoid treatment group). Solid bars are bronchi with diameters from 0.15 to 0.55 mm; open bars are bronchi with diameters greater than 0.55 mm. (A) shows that the contraction index prior to CCh-administration did not vary among the various retinoid treatment groups. After CCh-administration (B) the A/Ar was lower in VAD airways and was restored by retinoic acid (RA). (*) p < 0.05, VAD versus vitamin A sufficient (VAS). (#) p < 0.05, VAD + 12 days of RA versus VAD. Comparisons were between bronchi within the same range of diameters.