Dopamine for Pulmonary Diffusion and Capillary Blood Volume during Exercise. However, since the Layman Condition List is "Health" which is very broad, it is difficult to specify a specific condition for this trial

Overseen By Wade W Michaelchuk, BSc

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of Alberta

Must not be taking: Dopaminergic drugs, Alcohol

Disqualifiers: Cardiac disease, Pulmonary disease, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 7

Duration: 2-3 weeks

35 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

You may need to stop taking certain medications, especially those that affect dopamine pathways, like some drugs for mood or brain function, alcohol, and certain painkillers.

Is dopamine safe for use in humans during exercise?

Dopamine has been studied for its effects on exercise and cardiovascular responses, showing it can influence heart rate and blood pressure. Metoclopramide, a related drug, can decrease baroreflex sensitivity (the body's ability to maintain stable blood pressure) during exercise. These studies suggest dopamine and related drugs have some effects on the body during exercise, but they do not provide comprehensive safety data for all potential uses. ^{1 2 3 4 5}

How does the drug dopamine differ from other treatments for exercise-related pulmonary issues?

Dopamine is unique because it acts as a vasodilator (a substance that widens blood vessels) in the lungs, but studies show it does not improve exercise tolerance or pulmonary function during exercise in healthy individuals. Unlike other treatments that might enhance exercise performance, dopamine does not significantly change oxygen uptake or improve exercise capacity. ^{1 6 7 8 9}

What is the purpose of this trial?

The purpose of this study is to examine the effect of dopamine infusion and dopamine-2 receptor blockade on pulmonary capillary blood volume, diffusion, and the hemodynamic variables of pulmonary artery pressure, cardiac output, and pulmonary vascular resistance during exercise. Secondarily, this study will examine the effect of dopamine infusion and dopamine-2 receptor blockade on exercise tolerance.

Research Team

Michael K Stickland, PhD

Principal Investigator

University of Alberta

Eligibility Criteria

This trial is for healthy, physically active individuals with a BMI under 30 who exercise more than twice a week. It's not suitable for those with known heart or lung diseases, high BMI over 30, on certain medications affecting dopamine pathways, or women who are pregnant.

Inclusion Criteria

I do not have any known heart or lung diseases.

Physically active (exercising >2 times per week)

BMI < 30kg/m2

Exclusion Criteria

I am not taking drugs that affect dopamine in my brain.

I am not pregnant.

I have a known heart or lung condition.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

1 week

1 visit (in-person)

Baseline Testing

Pulmonary function and graded exercise testing to exhaustion to characterize aerobic fitness and lung function parameters

1 day

1 visit (in-person)

Treatment

Participants receive randomized treatments of dopamine, metoclopramide, or placebo with measurements at rest and during exercise

2-3 weeks

4 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

1 week

1 visit (in-person)

Treatment Details

Interventions

• Dopamine
• Metoclopramide

Trial Overview The study investigates how dopamine and blocking its receptors affect blood flow in the lungs and exercise tolerance. Participants will undergo different levels of exercise and receive either dopamine, metoclopramide (blocks dopamine-2 receptors), or placebos.

Participant Groups

Group I: Placebos Experimental Treatment 4 Interventions

Dependent variables measured with orally ingested placebo pill and intravenous saline at rest, 60%, and 85% of VO2max

Group II: Metoclopramide Experimental Treatment 4 Interventions

Dependent variables measured with oral metoclopramide ingestion at rest, 60%, and 85% of VO2max

Group III: Dopamine Experimental Treatment 4 Interventions

Dependent variables measured with intravenous low dose dopamine infusion at rest, 60%, and 85% of VO2max

Who Is Running the Clinical Trial?

University of Alberta

Lead Sponsor

Trials

957

Recruited

437,000+

Natural Sciences and Engineering Research Council, Canada

Collaborator

Trials

63

Recruited

3,000+

References

1. England pubmed.ncbi.nlm.nih.gov

The effect of dopamine on pulmonary diffusing capacity and capillary blood volume responses to exercise in young healthy humans. [2020]

2. England pubmed.ncbi.nlm.nih.gov

Dopaminergic modulation of exercise hyperpnoea via D(2) receptors in mice. [2013]

3. Netherlands pubmed.ncbi.nlm.nih.gov

Metoclopramide decreases baroreflex sensitivity in patients with essential hypertension. [2019]

4. United States pubmed.ncbi.nlm.nih.gov

Dopaminergic influence on cardiovascular responses to exercise stress in hypertensive subjects. [2019]

5. England pubmed.ncbi.nlm.nih.gov

Oxygen transport during dopamine infusion in dogs. [2019]

6. United States pubmed.ncbi.nlm.nih.gov

Acute inotropic stimulation with dopamine in severe congestive heart failure: beneficial hemodynamic effect at rest but not during maximal exercise. [2019]

7. England pubmed.ncbi.nlm.nih.gov

Dopamine receptor blockade improves pulmonary gas exchange but decreases exercise performance in healthy humans. [2022]

8. United States pubmed.ncbi.nlm.nih.gov

Effect of dopamine on transient ventilatory response to exercise. [2017]

9. Netherlands pubmed.ncbi.nlm.nih.gov

Decreased ventilatory response to exercise by dopamine-induced inhibition of peripheral chemosensitivity. [2013]