NCT07285031

Histamines and Central Hemodynamics

The Role of Histamines on Central Hemodynamics

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 20 (estimated)
• Sponsor: University of British Columbia · Academic / Other
• Sex: All
• Age: 19 Years – 39 Years
• Healthy volunteers: Accepted

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.

Conditions

• Histamine
• Exercise

Interventions

Type	Name	Description
DRUG	Diphenhydramine hydrochloride	H1 receptor antagonist: 50mg Diphenhydramine Hydrochloride
OTHER	Placebo	Placebo
OTHER	Exercise 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.

Timeline

• Start date: 2025-12-01
• Primary completion: 2026-08-01
• Completion: 2026-08-01
• First posted: 2025-12-16
• Last updated: 2025-12-23

Locations

1 site across 1 country: Canada