The effects of proprandolol and histamine on the ventilation response to carbon dioxide inhalation in normal subjects.

A method was developed to measure the oxygen cost of ventilation during CO2 rebreathing. In 20 healthy normal subjects SGaw, MMEF, and FEV1 were measured prior to and following the infusion of propranolol. In five of the same subjects airway constriction was induced by inhalation of histamine. The use of both agents was followed by a significant decrease in the ventilation response to carbon dioxide inhalation. Even more significantly, the oxygen cost of the increase in ventilation measured during CO2 rebreathing rose significantly following either propranolol or histamine.