Therapeutic Strategies to Reduce Endothelial Ischemia-reperfusion Injury

Conditions

• Endothelial Dysfunction
• Endothelial Function (reactive Hyperemia)
• Ischemic Preconditioning
• Metabolic Syndrome
• Vascular Injury

Eligibility Criteria

Sex

ALL

Age

18 Years - 65 Years

Healthy Volunteers

Accepted

Interventions

• Ischemic preconditioning — PROCEDURE
  The objective of this Intervention is to show that ischemic preconditioning (IPC) protects against endothelial ischemia/reperfusion injury. Baseline endothelium-dependent vasodilation to reactive hyperemia will be performed on the nondominant arm, followed by 3 × 5-minute cycles of IPC in the opposite arm. IPC will be induced using a blood pressure cuff placed on the opposite upper arm and inflated to 220 mmHg for 5 min, followed by 5 min of deflation. This procedure will be repeated two additional times taking about 30 minutest to complete. Following a 10-minute rest phase, endothelial injury will be induced using a blood pressure cuff that will be inflated to stop blood flow through the nondominant arm for 20 minutes, followed by 15 minutes of cuff deflation. Endothelium-dependent vasodilation measurements will be repeated immediately after the 15-minute cuff deflation phase.
• Intravenous lactate infusion — DRUG
  The objective of this Intervention is to show that an intravenous infusion of lactate protects against endothelial ischemia/reperfusion injury. Baseline endothelium-dependent vasodilation to reactive hyperemia will be performed on the nondominant arm. Thereafter, a continuous intravenous infusion of lactate will be delivered in the contralateral arm. After systemic lactate reaches \~3 mmol/L, endothelial injury will be induced using a blood pressure cuff that will be inflated to stop blood flow through the nondominant arm for 20 minutes, followed by 15 minutes of cuff deflation. Endothelium-dependent vasodilation measurements will be repeated immediately after the 15-minute cuff deflation phase.
• No ischemic preconditioning (control) — PROCEDURE
  The objective of this Intervention is to show that a control experiment without ischemic preconditioning does not provide protection against endothelial ischemia/reperfusion injury. Baseline endothelium-dependent vasodilation to reactive hyperemia will be performed on the nondominant arm, followed by 3 × 5-minute cycles of no upper arm occlusion in the opposite arm. To avoid upper arm occlusion, a blood pressure cuff will be placed on the upper arm and inflated to a low pressure of 20 mmHg pressure to not influence blood flow through the arm. This control procedure will be repeated two additional times taking about 30 minutes to complete. Following a 10-minute rest phase, endothelial injury will be induced using a blood pressure cuff that will be inflated to stop blood flow through the nondominant arm for 20 minutes, followed by 15 minutes of cuff deflation. Endothelium-dependent vasodilation measurements will be repeated immediately after the 15-minute cuff deflation phase.
• Normal Saline Infusion (Placebo) — DRUG
  The objective of this Intervention is to show that a placebo intravenous infusion does not protect against endothelial ischemia/reperfusion injury. Baseline endothelium-dependent vasodilation to reactive hyperemia will be performed on the nondominant arm. Thereafter, a continuous infusion of normal saline that does not contain lactate will be delivered in the contralateral arm. After 20 minutes of the placebo infusion, endothelial injury will be induced using a blood pressure cuff that will be inflated to stop blood flow through the nondominant arm for 20 minutes, followed by 15 minutes of cuff deflation. Endothelium-dependent vasodilation measurements will be repeated immediately after the 15-minute cuff deflation phase.
• Ischemic preconditioning and intravenous lactate — COMBINATION_PRODUCT
  The objective of this Intervention is to show that combining ischemic preconditioning (IPC) with an intravenous infusion of lactate provides the best protection against endothelial injury. First, baseline endothelial function to reactive hyperemia will be performed on the nondominant arm. Thereafter, a continuous intravenous infusion of lactate will be delivered in the contralateral arm. After that investigators will administer IPC using a blood pressure cuff placed on the same upper arm and inflated to 220 mmHg for 5 min, followed by 5 min of deflation. This procedure will be repeated two more times taking about 30 minutes to complete. The intravenous lactate infusion will be maintained. After a 10-minute rest phase and while lactate is still being infused, endothelial injury will be induced using a blood pressure cuff inflated to stop blood flow through the opposite arm (nondominant arm) for 20 minutes, followed by 15 minutes of cuff deflation. Endothelial function will be repeated.

Study Details

The objective of this clinical trial is to better understand how lactate, a naturally occurring energy substance, can be used to lessen damage to the vascular system in adults with a high cardiovascular disease risk. The main questions it aims to answer are: 1. Does giving lactate intravenously reduce injury to the vascular system? 2. Does giving lactate intravenously together with blood flow occlusion - known as ischemic preconditioning, reduce vascular injury better than blood flow occlusion by itself? 3. How does lactate help the vascular system? Researchers will compare lactate to a placebo (a look-alike substance that contains no lactate) to see if lactate works to lessen vascular injury. Researchers will also compare lactate to blood flow occlusion to see which one is better at preventing vascular injury. Researchers will also compare lactate and blood flow occlusion together to see if combining them works better than either one alone. In one visit to the laboratory, participants will: Obtain a measurement of vascular health in an arm Be given liquid lactate, a liquid placebo, and/or arm blood flow occlusion Obtain a second measurement of vascular health in an arm.

Key Dates

Start date

Oct 1, 2026

Status verified

Jan 2025

Primary completion

Sep 30, 2029

Completion

Jun 30, 2030

Study Design

Enrollment

68 participants (estimated)

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Arms

• Active Comparator: Ischemic preconditioning versus intravenous lactate infusion
  To goal of this Arm is to compare the capacity of ischemic preconditioning (IPC) to protect against endothelial ischemia/reperfusion injury to the capacity of an intravenous lactate infusion to protect against endothelial ischemia/reperfusion injury. To achieve this goal, investigators will test the hypothesis that the capacity for intravenous lactate to reduce endothelial injury will be equivalent to that of IPC. Participants will be randomized to one of two Interventions. One Intervention will be the IPC intervention which is thought to be effective in treating the condition under study. The other intervention is the intravenous lactate intervention, which is the main focus of the study.
• Experimental: Ischemic preconditioning combined with an intravenous lactate infusion
  To goal of this Arm is to compare the capacity of ischemic preconditioning (IPC) combined with an intravenous lactate infusion to protect against endothelial ischemia/reperfusion injury to IPC by itself. To achieve this goal, investigators will test the hypothesis that the capacity to protect against endothelial injury will be better when IPC and lactate are combined compared to IPC alone. Participants will be randomized to one of two Interventions. One Intervention will be the IPC intervention by itself. The other intervention will be adding an intravenous lactate infusion together with IPC which is the main focus of the study.

Primary Outcome Measure

Baseline value of the mean peak forearm blood flow response to reactive hyperemia. [ Time Frame: Baseline (time 0) ]

Central Contacts

• Gary P Van Guilder, PhD
  970-943-7133
  [email protected]

Locations (1)

Find similar trials in Gunnison, CO

Related Studies

• Obesity, Metabolic Dysregulation and the Airway Epithelium in Asthmatics
  Recruiting · University of Colorado, Denver · Aurora, Colorado
• Bright Light Exposure in Surgical Patients
  Recruiting · University of Colorado, Denver · Denver, Colorado
• Puberty Suppression and Cardiometabolic Health
  Recruiting · University of Colorado, Denver · Aurora, Colorado
• Inspiratory Muscle Strength Training for Lowering Blood Pressure and Improving Endothelial Function in Postmenopausal Women: Comparison With "Standard of Care" Aerobic Exercise
  Recruiting · University of Colorado, Boulder · Boulder, Colorado