Clinical Evidence of pH Dependent ß2 Adrenergic Transport Mechanisms in the Airway
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|ClinicalTrials.gov Identifier: NCT01216748|
Recruitment Status : Completed
First Posted : October 7, 2010
Results First Posted : December 17, 2014
Last Update Posted : May 27, 2016
|Condition or disease||Intervention/treatment||Phase|
|Healthy Volunteers||Other: quiet breathing Other: Hypocapnic Hyperventilation Other: Hypercapnic Hyperventilation Other: eucapnic hyperventilation||Not Applicable|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||10 participants|
|Intervention Model:||Single Group Assignment|
|Masking:||None (Open Label)|
|Primary Purpose:||Basic Science|
|Official Title:||Clinical Evidence of pH Dependent ß2 Adrenergic Transport Mechanisms in the Airway|
|Study Start Date :||January 2010|
|Actual Primary Completion Date :||July 2010|
|Actual Study Completion Date :||August 2010|
Experimental: health life-time non smokers
health lifetime non-smokers will be challenged with 4 respiratory maneuvers:quiet breathing, hypocapnic hyperventilation, hypercapnic hyperventilation, and eucapnic hyperventilation
Other: quiet breathing
Subjects were instructed to breath normally at room air.
Other: Hypocapnic Hyperventilation
hypocapnic hyperventilation, the subjects were instructed to breathe fast and deep until their end-tidal pCO2 fell to 30 mmHg, corresponding to a systemic pH increase of about 0.1 pH units.
Other: Hypercapnic Hyperventilation
For hypercapnic hyperventilation, a modification of a previously described procedure (15). While monitoring SaO2 using pulse oximetry and end-tidal CO2 by mass-spectrometry on a breath by breath basis, CO2 was bled into the inspired air to achieve an end-tidal pCO2 of at least 55 mmHg
Other: eucapnic hyperventilation
For eucapnic hyperventilation, the subjects were instructed to increase their ventilation to the highest level of ventilation recorded in the previous two hyperventilation maneuvers, while CO2 was bled into the inspired air to maintain end-tidal pCO2 at 40 mmHg.
- Changes in Airway Blood Flow After 180μg Albuterol by Inhalation (ΔQaw) vs Baseline [ Time Frame: 15 minutes after albuterol inhalation ]Effect of airway pH on albuterol responsiveness as reflected by the change in airway blood flow after 180μg albuterol by inhalation (ΔQaw) vs baseline.
- Exhaled Breath Condensate (EBC) pH Variation [ Time Frame: 10 minutes after each respiratory manouver. ]
EBC samples were collected at each respiratory maneuver by directing the subject's exhaled breath into a pre-cooled (-10C) tube for 10 min.
pH was measured immediately after collection.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01216748
|United States, Florida|
|Pulmonary Human Research Laboratory, University of Miami School of Medicine|
|Miami, Florida, United States, 33136|
|Principal Investigator:||Matthias Salathe||University of Miami|