Bronchopulmonary influences in larynx resistance

Abstract

Larynx resistance changes have been studied in the dog by means of in situ isolated glottis technique. Bronchiolar tone changed through isoprenaline and histamine administration, and after recurrent and vagus nerve bilateral section. Isoprenaline administration (0.1 mg/kg) was followed by larynx resistance decrease, expiratory duration increase, and expiratory abdominal pressure decrease with regard to respiration preceded by rest. Cough response by mechanical tracheal stimulation and glottis closing by larynx stimulation were abolished after isoprenaline administration. Histamine administration (0.1 mg/kg) was followed by larynx resistance increase, expiratory duration decrease, expiratory abdominal pressure increase, and expiratory abdominal pressure/maximum expiratory airflow relation increase. Larynx resistance decreased after recurrent nerve bilateral section, and increased later when vagus nerves were sectioned.