Vitamin A deficiency (VAD) remains an important problem in the developing world where
environmental air pollution is increasing. Because the coincidence of these factors could
increase the prevalence of asthma in these regions, airway reactivity to methacholine (MCh),
capsaicin, and sulfur dioxide was studied in VAD rats. The impedance to a small volume
oscillation was analyzed to determine airway resistance (Raw) and lung elastance (H). VAD
rats demonstrated larger increases in Raw and H after the administration of methacholine …