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Histamines and Central Hemodynamics

ConditionsHistamineExercise
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age19-39
SponsorUniversity of British Columbia

About this trial

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.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

Age: 19 - 39.

Willing to visit the lab on 3 separate occasions.

Disqualifiers

Previously diagnosed heart condition,

Previously diagnosed lung condition (including asthma),

Previously diagnosed metabolic condition,

Currently smokers (cigarettes, electronic cigarettes, cannabis) or who have smoked within the last 3 months,

Trial design

Design model

Crossover

Treatments tested in this trial

  • Diphenhydramine hydrochloride

    Drug

    H1 receptor antagonist: 50mg Diphenhydramine Hydrochloride

  • Placebo

    Other intervention

    Placebo

  • Exercise Bout

    Other intervention

    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.

Treatment groups

20 Participants
are divided into 2 treatment groups
Group A: Blockade + Exercise BoutExperimental treatment 2 interventions
Group B: Placebo + Exercise BoutPlacebo comparator 2 interventions

Trial outcomes

Primary outcomes

1

Systolic pulmonary artery pressure

The difference in systolic pulmonary artery pressure (measured as tricuspid regurgitation velocity using echocardiography) between the H1 blockade condition and the placebo condition.

Time frame
Pre-exercise and 10, 20, and 30-minutes post-exercise.

Secondary outcomes

1

Tricuspid annular plane systolic displacement

The difference in tricuspid annular plane systolic displacement between the H1 receptor blockade condition and the placebo condition.

Time frame
Pre-exercise and 0, 10, 20, 30, 45, and 60 minutes post-exercise.
2

Right ventricular stroke volume

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.

Time frame
Pre-exercise and 0, 10, 20, 30, 45, and 60-minutes post-exercise.
3

Femoral artery blood flow

The difference in femoral artery blood flow between the H1 receptor blockade condition and the placebo condition.

Time frame
Pre-exercise and 0, 10, 20, 30, 45, and 60-minutes post-exercise.
4

Mean arterial systemic pressure

The difference in mean arterial systemic pressure between the H1 receptor blockade condition and the placebo condition.

Time frame
Pre-exercise and 0, 10, 20, 30, 45, and 60-minutes post-exercise.

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

University of British Columbia

Lead sponsor

Source ClinicalTrials.gov
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