Histamine, Exercise
Conditions
Keywords
histamine, exercise, pulmonary blood flow, pulmonary function, femoral blood flow
Brief summary
When we exercise, more blood flow goes to our muscles, challenging our blood vessels. Following exercise, blood flow remains elevated and seems to be the reason for many of the positive cardiovascular benefits that occur with exercise. When the actions of histamine, a molecule primarily known for its role in allergies, are blocked, there is an attenuated blood flow response following exercise. However, this effect has never been studied in the blood vessels that supply our lungs. The purpose of this study is to examine the effects of histamines on pulmonary hemodynamics following exercise.
Interventions
H1 receptor antagonist: 50mg Diphenhydramine Hydrochloride
OTHERPlacebo
Placebo
OTHERExercise Bout
Participants will complete a total of three 5-minute high intensity exercise intervals, interspersed with 5-minute lower intensity exercise bouts (4 total), for a total of 35 minutes.
Sponsors
University of British Columbia
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
19 Years to 39 Years
Healthy volunteers
Yes
Inclusion criteria
1. Age: 19 - 39. 2. Willing to visit the lab on 3 separate occasions.
Exclusion criteria
1. Previously diagnosed heart condition, 2. Previously diagnosed lung condition (including asthma), 3. Previously diagnosed metabolic condition, 4. Currently smokers (cigarettes, electronic cigarettes, cannabis) or who have smoked within the last 3 months, 5. Resting blood pressure \>140/90 mmHg, 6. Unable to obtain appropriate quality ultrasound images of the heart., 7. Individuals without tricuspid regurgitation at rest to allow assessment of the primary outcome, 8. Pregnant or trying to become pregnant, 9. Breastfeeding, 10. Chronically take antihistamines (i.e. daily), 11. History of adverse reactions to antihistamines, 12. Never taken antihistamines previously, 13. Currently taking any medications (including oral contraceptives).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Systolic pulmonary artery pressure | Pre-exercise and 10, 20, and 30-minutes post-exercise. | The difference in systolic pulmonary artery pressure (measured as tricuspid regurgitation velocity using echocardiography) between the H1 blockade condition and the placebo condition. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Tricuspid annular plane systolic displacement | Pre-exercise and 0, 10, 20, 30, 45, and 60 minutes post-exercise. | The difference in tricuspid annular plane systolic displacement between the H1 receptor blockade condition and the placebo condition. |
| Right ventricular stroke volume | Pre-exercise and 0, 10, 20, 30, 45, and 60-minutes post-exercise. | The difference in right ventricular stroke volume (measured using pulsed wave velocity of the right ventricular outflow tract velocity time integral) between the H1 receptor blockade condition and the placebo condition. |
| Femoral artery blood flow | Pre-exercise and 0, 10, 20, 30, 45, and 60-minutes post-exercise. | The difference in femoral artery blood flow between the H1 receptor blockade condition and the placebo condition. |
| Mean arterial systemic pressure | Pre-exercise and 0, 10, 20, 30, 45, and 60-minutes post-exercise. | The difference in mean arterial systemic pressure between the H1 receptor blockade condition and the placebo condition. |
Countries
Canada
Contacts
Primary ContactNeil Eves, PhD
Backup ContactCassidy Williams, BHK
Outcome results
None listed