Cerebrovascular Responses to Acute Hypoperfusion
University of Wisconsin, Madison
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.
Description
Global cerebral blood flow (CBF) decreases with advancing age; however, some adults have accelerated declines in CBF, placing them at a greater risk of cognitive impairment. However, there is a lack of human studies that investigate the cause or consequence of altered blood flow regulation in the brain. This study will systematically address this gap in knowledge by examining cerebrovascular control in adults during acute physiological challenges (simulated postural change test and breathing increased carbon dioxide) that stimulate a change in CBF.
Eligibility
- Age range
- 55–69 years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * 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 Exclusion Criteria: * 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 tac…
Interventions
- DeviceMRI
Participants will undergo an MRI scan while performing breathing and a simulated postural change task.
- DrugPrazosin
A dose of prazosin will be administered based on body weight.
- DrugPlacebo
Oral placebo
Location
- University of WisconsinMadison, Wisconsin