Brief Summary

Many acute and chronical medical conditions, such as, shock, sepsis, diabetes, hypertonia, and cardiovascular disease are associated with a perturbated or lost ability of regulating the diameter of the blood vessels. These changes in regulatory function can be seen especially in the smaller vessels in the body. It is therefore clinically relevant to develop investigation models that can detect and quantify such changes at an early stage. Historically, basic vascular function was investigated by mounting a section of a blood vessel on a tension sensor, submerging it in a temperature controlled and buffered solution to which vasoactive substances were added. This in vitro model has contributed substantially to our current knowledge of vascular pharmacology and function. However, using this method means that the vessel is removed from its natural environment and, hence no longer influenced by systemic or local mediators for controlling vessel diameter. The present study aims to investigate the local changes in blood flow and concentration of red blood cells of the superficial vessels in the skin of the forearm of healthy volunteers in response to various vasoactive substances. The purpose is to better understand how the regulation of diameter works in and to find a model that can give an early warning to when it does not function optimally. The vasoactive substances will be delivered through the skin to the vascular bed by a non-invasive method called iontophoresis. An electrode chamber containing a solution of the substance to be studied is placed on the subject's skin by double adhesive tape. The chamber comes with a transparent lid that prevents leakage and enables supervision of the effect on the underlying vasculature. When a voltage is applied the charged drug molecules begin to move through the skin and interact with the vessels. In the present study, a total electrical dose of 12 millicoulomb (mC) is going to be used (600 seconds x 0.02 milliampere). The effect of the applied drug is measured using two non-contact, optical measurement techniques. A better understanding of the pharmacology and regulation of blood vessels may lead to the developement of techniques that allow earlier detection of perturbations in vessel regulation and the onset of preventive medical treatment.

Trial Health

At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date

Enrollment

participants targeted

Target at P25-P50 for not_applicable cardiovascular-diseases

Timeline

Completed

Started Apr 2019

Typical duration for not_applicable cardiovascular-diseases

Geographic Reach

1 country

1 active site

Status

unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

2.8 years study duration

Study Start

First participant enrolled

April 1, 2019

Completed

1.9 years until next milestone

First Submitted

Initial submission to the registry

February 22, 2021

Completed

8 days until next milestone

First Posted

Study publicly available on registry

March 2, 2021

Completed

10 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2021

Completed

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2021

Completed

Last Updated

March 2, 2021

Status Verified

February 1, 2021

Enrollment Period

2.8 years

First QC Date

February 22, 2021

Last Update Submit

February 25, 2021

Conditions

Cardiovascular Diseases Vascular Diseases

Keywords

iontophoresispharmacologytissue viability imagingmulti-exposure laser speckle contrast imaging

Outcome Measures

Primary Outcomes (1)

Locally induced changes in red blood cell concentration and movement due to iontophoresis of vasoactive substances.
Optically derived arbitrary values that correlate to the concentration and movement of red blood cells in the vessels.
Measured prior the onset of iontophoresis (baseline), then continuously for the duration of the iontophoretic pulse (10 minutes) and for the 30 minute wash-out period following each iontophoretic pulse.

Study Arms (1)

Vascular effects of iontophoresed vasoactive substances

EXPERIMENTAL

Iontophoretically administered vasoactive substances in five concentrations (1%,0.1%,0.01%,0.001%, 0.0001%) dissolved in sterile water. Each concentration of the drug is separately administered using a electrical charge of 12 millicoulomb (mC) (600 seconds x 0.02 milliampere) for 3 repeated pulses (total electrical charge 36 mC). Each iontophoresis pulse is separated by a 30 minute wash-out period. Vasoactive substances: * Miochol-E (Acetylcholine),10 mg/ml, Bausch \& Lomb * Methacholine chloride, 100 mg/ml, APL * Norepinephrine, 1 mg/ml, Pfizer * Phenylephrine, 10 mg/ml, Unimedic * Atropine, 10 mg/ml, Bausch \& Lomb * Neostigmine, 2.5 mg/ml, Unimedic Pharma * Sterile water, 100 ml, Braun

Drug: AcetylcholineDrug: NorepinephrineDrug: PhenylephrineDrug: AtropineDrug: NeostigmineDrug: Sterile water