Endothelial FunctionEarly Phase 1CAP NOVANCT06499844
Comparing Approaches to Assess Nitric Oxide-dependent Cutaneous Vasodilation
A Early Phase 1 study testing Acetylcholine in people with Endothelial Function, run by University of Iowa at 1 site in United States.
Trial summary
The increase in skin blood flow in response to rapid local heating of the skin (i.e., cutaneous vasodilation) is commonly used to assess nitric oxide (NO)-dependent dilation and overall microvascular function. Historically, rapid local heating to 42°C was considered the standard approach for these assessments. Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Endothelial Function
- What is being tested?
- Acetylcholine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 56 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Aug 2024to Feb 2027
- Phase
- Early Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 30 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- men and women
- 18-30 years of age
Who cannot join
- Current or recent (within 8 wks) use of medication that could conceivably alter microvascular function [including (but not limited to) stimulants, antihypertensives, HMG-CoA reductase inhibitors]
- Changes or alterations in medication status (starting a new, additional, or different medication or changing the dose of a current medication)
- Unstable or diagnosed chronic clinical disease, including cardiovascular, metabolic, renal, hepatic, autonomic, autoimmune, or dermatological disease (e.g., hypertension, heart disease, diabetes, hyperlipidemia, psoriasis)
- Body mass index <18.5 or >35 kg/m2
- Pregnancy (including a positive urine pregnancy test) or breast-feeding
- Known allergies to pharmacological agents or study drugs
- Non-English-speaking. Participants need to understand English to follow instructions and comply with procedures conducted during the screening and experimental visits.
Trial locations and contacts
1 site in 1 country.
About this study
The increase in skin blood flow in response to rapid local heating of the skin (i.e., cutaneous vasodilation) is commonly used to assess nitric oxide (NO)-dependent dilation and overall microvascular function. Historically, rapid local heating to 42°C was considered the standard approach for these assessments. More recently, many investigators have adopted rapid local to 39°C instead, based on its larger dependency on NO and therefore improved ability to quantify NO-dependent dilation without the use of pharmacological techniques. However, to date, only one direct methodological comparison between these protocols has been performed.
In this study, the investigators use the blood vessels in the skin as a representative vascular bed for examining mechanisms of microvascular dysfunction in humans. Using a minimally invasive technique (intradermal microdialysis for the local delivery of pharmaceutical agents) they examine the blood vessels in a nickel-sized area of the skin in young adults ages 18 - 30 years old. Local heating of the skin at the microdialysis sites is used to explore differences in mechanisms governing microvascular control. As a compliment to these measurements, the investigators also have participants fill out a variety of surveys to assess things such as sleep quality, physical activity, daily stressors, etc.
- Conditions
- Endothelial Function
- Being tested
- Acetylcholine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AcetylcholineDrug
acetylcholine, and acetylcholine + L-NAME (Nitric oxide synthase inhibitor) are locally and acutely delivered to the cutaneous microvasculature to assess endothelium- and nitric oxide-dependent dilation
| Study group | Role | What they receive |
|---|---|---|
| assessment of microvascular endothelial function | Experimental | The investigators use intradermal microdialysis to deliver acetylcholine, L-NAME, and acetylcholine + L-NAME to the cutaneous microvasculature. Receives: Drug: Acetylcholine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Microvascular blood flow response to acetylcholine
cutaneous vascular vasodilator response to exogenous acetylcholine perfusion; measured with laser-Doppler flowmetry coupled with intradermal microdialysis delivery of acetylcholine alone or co-infused with L-NAME
Measured: baseline study visit (average of 4 hours)
Microvascular blood flow response to local heat (42 degrees Celsius)
cutaneous vascular vasodilator response to 42 degree local heat; measured with laser-Doppler flowmetry coupled with intradermal microdialysis delivery of lactated Ringer's, followed by L-NAME.
Measured: baseline study visit (average of 4 hours)
Microvascular blood flow response to local heat (39 degrees Celsius)
cutaneous vascular vasodilator response to 39 degree local heat; measured with laser-Doppler flowmetry coupled with intradermal microdialysis delivery of lactated Ringer's, followed by L-NAME.
Measured: baseline study visit (average of 4 hours)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Jul 2024
- Study start1 Aug 2024
- Primary completion12 Aug 2025
- Study completionFeb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Endothelial FunctionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- All participants will complete one laboratory visit to assess endothelial function in the cutaneous microvasculature.
- Masking
- None (open label)
- Enrolment
- 56 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Iowa
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Anna Stanhewicz, PhD, University of Iowa
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06499844
- Sponsor's protocol ID
- 202404816
- Acronym
- CAP NOVA
- Status last verified
- Oct 2026
- First submitted
- 26 Jun 2024
- Last updated
- 29 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 29 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparing Approaches to Assess Nitric Oxide-dependent Cutaneous Vasodilation
- ClinicalTrials.gov ID
- NCT06499844
- Acronym / sponsor ID
- CAP NOVA / 202404816
- Conditions
- Endothelial Function
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 56 participants (estimated)
- Lead sponsor
- University of IowaUniversity, hospital or other
- Study start
- 1 Aug 2024 (actual)
- Primary completion
- 12 Aug 2025 (actual)
- Study completion
- Feb 2027 (estimated)
- First posted
- 15 Jul 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The increase in skin blood flow in response to rapid local heating of the skin (i.e., cutaneous vasodilation) is commonly used to assess nitric oxide (NO)-dependent dilation and overall microvascular function. Historically, rapid local heating to 42°C was considered the standard approach for these assessments. More recently, many investigators have adopted rapid local to 39°C instead, based on its larger dependency on NO and therefore improved ability to quantify NO-dependent dilation without the use of pharmacological techniques. However, to date, only one direct methodological comparison between these protocols has been performed.
In this study, the investigators use the blood vessels in the skin as a representative vascular bed for examining mechanisms of microvascular dysfunction in humans. Using a minimally invasive technique (intradermal microdialysis for the local delivery of pharmaceutical agents) they examine the blood vessels in a nickel-sized area of the skin in young adults ages 18 - 30 years old. Local heating of the skin at the microdialysis sites is used to explore differences in mechanisms governing microvascular control. As a compliment to these measurements, the investigators also have participants fill out a variety of surveys to assess things such as sleep quality, physical activity, daily stressors, etc.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- All participants will complete one laboratory visit to assess endothelial function in the cutaneous microvasculature.
| Arm | Type | Receives |
|---|---|---|
| assessment of microvascular endothelial function | Experimental | Drug: AcetylcholineThe investigators use intradermal microdialysis to deliver acetylcholine, L-NAME, and acetylcholine + L-NAME to the cutaneous microvasculature. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- men and women
- 18-30 years of age
Key exclusion criteria (7 listed)
- Current or recent (within 8 wks) use of medication that could conceivably alter microvascular function [including (but not limited to) stimulants, antihypertensives, HMG-CoA reductase inhibitors]
- Changes or alterations in medication status (starting a new, additional, or different medication or changing the dose of a current medication)
- Unstable or diagnosed chronic clinical disease, including cardiovascular, metabolic, renal, hepatic, autonomic, autoimmune, or dermatological disease (e.g., hypertension, heart disease, diabetes, hyperlipidemia, psoriasis)
- Body mass index <18.5 or >35 kg/m2
- Pregnancy (including a positive urine pregnancy test) or breast-feeding
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Acetylcholineacetylcholine, and acetylcholine + L-NAME (Nitric oxide synthase inhibitor) are locally and acutely delivered to the cutaneous microvasculature to assess endothelium- and nitric oxide-dependent dilation | Drug | assessment of microvascular endothelial function |
Primary outcome
Microvascular blood flow response to acetylcholine
Time frame: baseline study visit (average of 4 hours)
cutaneous vascular vasodilator response to exogenous acetylcholine perfusion; measured with laser-Doppler flowmetry coupled with intradermal microdialysis delivery of acetylcholine alone or co-infused with L-NAME
Microvascular blood flow response to local heat (42 degrees Celsius)
Time frame: baseline study visit (average of 4 hours)
cutaneous vascular vasodilator response to 42 degree local heat; measured with laser-Doppler flowmetry coupled with intradermal microdialysis delivery of lactated Ringer's, followed by L-NAME.
Microvascular blood flow response to local heat (39 degrees Celsius)
Time frame: baseline study visit (average of 4 hours)
cutaneous vascular vasodilator response to 39 degree local heat; measured with laser-Doppler flowmetry coupled with intradermal microdialysis delivery of lactated Ringer's, followed by L-NAME.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing Acetylcholine in people with Endothelial Function, run by University of Iowa at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 29 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Microvascular blood flow response to acetylcholine (time frame: baseline study visit (average of 4 hours)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Oct 2026; AzTrials last refreshed its copy on 31 Oct 2026.