Mucociliary Tran sport in Chickens Infected with Newcastle Disease Virus and Exposed to Sulfur Dioxide

Abstract

Mucociliary transport was studied in the nasal mucous membranes and sinuses of 3-week-old chickens which were either exposed to sulfur dioxide (SO₂), infected intranasally with the mesogenic strain of Newcastle disease virus (NDV), or exposed to SO₂ after NDV infection. A newly developed apparatus was used to follow intranasal transport rates over time in the same animal, and to follow sinus transport rates over time in a separate group of animals.

Intermittent exposure to concentrations of 1.4–66.0 ppm SO₂ produced peaks of increased intranasal transport time, with intervening recovery periods. This suggests a homeostatic mechanism. Transport was also decelerated in the sinus when concentrations of SO₂ were above 10 ppm. NDV infection produced decelerated intranasal transport rates but did not decelerate sinus rates. Combined NDV and SO₂ interacted to produce persistent deceleration of the intranasal transport rate. In the sinus, the combination seemed to counteract the decelerating effect of SO₂ alone, suggesting a separate mechanism of homeostasis.