Measurement of specific airway conductance in guinea pigs. A noninvasive method.

A constant volume plethysmographic technique has been developed to measure specific airway conductance (sGaw) in unanesthetized spontaneously breathing guinea pigs. The technique utilizes a specially designed animal restraining device and mask piece. sGaw is measured at end-expiration and does not require knowledge of thoracic gas volume. Control values are within the range reported previously for this species. The method is noninvasive with minimum stress to the animals. Exposure of guinea pigs to an aerosol of cotton dust extract produces similar qualitative changes (a fall) in sGaw to those observed in human volunteers exposed to the same aerosol. The method is proposed as a suitable model for the study of byssinosis (the occupational lung disease associated with chronic exposure to cotton dust). The technique may also be applied to the acute and chronic study of the airway response to other airborne pharmacological and toxicological agents.