Endothelial Function
Conditions
Brief 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. 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.
Interventions
DRUGAcetylcholine
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
Sponsors
University of Iowa
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
All participants will complete one laboratory visit to assess endothelial function in the cutaneous microvasculature.
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
* men and women * 18-30 years of age
Exclusion criteria
* 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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Microvascular blood flow response to acetylcholine | 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) | 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) | 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. |
Countries
United States
Contacts
Primary ContactAnna Stanhewicz, PhD
Outcome results
None listed