Brain Blood Vessel Responses to Changes in Blood Flow

NCT06629077 | Recruiting Phase 2 FDA Drug

• 5 other identifiers: 2024-03771RF1NS117746-01A176000EDUC/KINESIOLOGYProtocol Version7/29/2025
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

Brief Summary

Brain blood flow will be measured during a simulated postural change test and while breathing increased levels of carbon dioxide using magnetic resonance imaging.

Conditions

Magnetic Resonance Imaging; Cerebrovascular Circulation

Keywords

Magnetic Resonance Imaging; Brain Blood Flow; Lower Body Negative Pressure; Carbon Dioxide

Outcome Measures

Primary Outcomes (2)

• Change in blood flow

  The change in intracranial blood flow during breathing and simulated postural change tasks will be measured with MRI

  Two study visits, up to 240 minutes

• Change in blood velocity

  The change in blood velocity during breathing and simulated postural change tasks will be measured with MRI.

  Two study visits, up to 240 minutes

Study Arms (1)

Middle-Aged Adults

EXPERIMENTAL

Middle-Aged Adults between 55-69 years of age.

Device: MRI; Drug: Prazosin; Drug: Placebo

Interventions

Placebo DRUG

Oral placebo

Middle-Aged Adults

MRI DEVICE

Participants will undergo an MRI scan while performing breathing and a simulated postural change task.

Middle-Aged Adults

Prazosin DRUG

A dose of prazosin will be administered based on body weight.

Middle-Aged Adults

Eligibility Criteria

• Age: 55 Years - 69 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Between the ages of 55-69 years
• Have a BMI less than or equal to 34.5 kg/m2
• Nonsmoker
• are less than 72 in (182.88 cm) height
• Females must be postmenopausal

You may not qualify if:

• Diagnosis of Mild Cognitive Impairment (MCI) or Alzheimer's disease (AD)
• History or evidence of hepatic disease, hematological disease, or peripheral vascular disease; severe kidney injury requiring hemodialysis
• History of cardiovascular disease including: severe congestive heart failure, coronary artery disease, ischemic heart disease (stents, coronary artery bypass grafts) and tachycardia
• Uncontrolled hypertension
• History of clinically significant ischemic or hemorrhagic stroke, or significant cerebrovascular disease
• Severe untreated obstructive sleep apnea
• History of diabetes with HbA1c greater than 9.5%
• Major neurologic disorders other than dementia (e.g., MS, ALS, brain surgery, etc.)
• Current or recent (\<1 year) major psychiatric condition (Axis I) or addictive disorders
• Significant surgical history
• Other significant medical conditions at investigators' discretion
• Contraindications to MRI
• Prescribed medications that interfere with prazosin
• Lactose allergy
• lower body will not fit in lower body negative pressure (LBNP) chamber (regardless of overall height and BMI).

Sponsors & Collaborators

• University of Wisconsin, Madison: lead
• National Institute of Neurological Disorders and Stroke (NINDS): collaborator

Study Sites (1)

University of Wisconsin

Madison, Wisconsin, 53705, United States

RECRUITING

MeSH Terms

Interventions

Prazosin

Intervention Hierarchy (Ancestors)

Quinazolines; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds

Study Officials

• Jill Barnes, PhD

  UW Madison

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Anna Howery

CONTACT

608-262-9572; ahowery@wisc.edu

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 4, 2024
• First Posted: October 8, 2024
• Study Start: February 26, 2026
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): January 1, 2027
• Last Updated: March 2, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)