Ventilatory Response to CO2 Rebreathing After Adrenergic Blockade in Goats,
Abstract
Administration of adrenergic agonists enhances resting ventilation and increases responsiveness to C02 inhalation, though there are conflicting data about the effect of adrenergic blockade on ventilatory responses. In this study, we investigated the effect of alpha- or beta-adrenergic blockade on the ventilatory response to hyperoxic C02 rebreathing in awake goats. Five goats were studied before and after intravenous administration of phentolamine (3.8 mg bolus followed by 0.19 mg/min) or propranolol (0.15 mg/kg). Adequacy of alpha- or beta-adrenergc blockade was subsequently demonstrated by assessing the pressor response to norepinephrine or the heart rate response to isoproterenol, respectively. There was no difference (compared to control studies) in the mean slope, x-intercept, or ventilation at end-tidal PC02 = 70 torr for the C02 response curves after the goats had received either phentolamine or propranolol. When mean inspiratory flow rate (VT/Ti) was plotted against end-tidal PCO2, there was also no change in slope x-intercept or VT/Ti at end-tidal PCO2 = 70 torr after the goats had received propranolol.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 25, 1983
- Accession Number
- ADA126279
Entities
People
- David E. Leith
- Richard A. Steinbrook
- Richard Harris
- Ronald A. Gabel
- Steven E. Weinberger
Organizations
- United States Army Research Institute of Environmental Medicine