Effects of Urocortins on Forearm Arterial Blood Flow in Healthy Volunteers (Protocol 2)

This study has suspended participant recruitment.
(Awaiting supply of peptide from a different company)
Sponsor:
Collaborator:
NHS Lothian
Information provided by (Responsible Party):
University of Edinburgh
ClinicalTrials.gov Identifier:
NCT01096693
First received: March 30, 2010
Last updated: May 10, 2012
Last verified: May 2012
  Purpose

Impairment of the heart's pumping capacity (heart failure) remains a major clinical problem with a poor prognosis and the search for novel treatments remains an important area of research.

Urocortins are proteins that appear to increase blood flow and heart pumping activity. There has been particular interest in the role of Urocortins 2 & 3 (subtypes of Urocortins) in heart failure.

In this study, we will examine the effects and mechanisms of Urocortins 2 & 3 and the Corticotrophin Releasing Hormone Receptor Type 2 (CRH-R2) receptor (through which urocortins act) on forearm blood flow and release of natural blood clot dissolving factors in the forearm circulation of healthy volunteers.

In this study, we will look at the role of the lining of the blood vessel (endothelium) in response to urocortin types 2 and 3. We hypothesise that urocortins 2 & 3 act via the endothelium to cause dilatation of the blood vessels and release of tissue-plasminogen activating factor (blood clot dissolving factor). We also hypothesise that urocortins have a role in maintaining the normal baseline level of blood flow in forearm arteries. In addition to the above, we will also look at the effect of temporarily blocking the effect of urocortins, using a specially designed blocker drug (Astressin 2B).

Utilising the well-established technique of 'forearm venous occlusion plethysmography', we will be able to focus on the local effects of urocortins on arterial blood flow in forearm vessels, without affecting this system in the body as a whole.


Condition Intervention
Vascular Disease
Heart Disease
Drug: Urocortin 2, Urocortin 3
Drug: Saline placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacokinetics/Dynamics Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Basic Science
Official Title: Effects of Urocortins on Forearm Arterial Blood Flow in Healthy Volunteers

Resource links provided by NLM:


Further study details as provided by University of Edinburgh:

Primary Outcome Measures:
  • Forearm blood flow [ Time Frame: 2.30 hours ] [ Designated as safety issue: No ]
    Difference between forearm blood flow in response to doses of Ucn2, Ucn3 and Substance P in the presence vs absence of Astressin 2B dose 1 and in the presence vs absence of Astressin 2B dose 2


Secondary Outcome Measures:
  • Net t-PA release [ Time Frame: 2.30 hours ] [ Designated as safety issue: No ]
    Net t-PA release induced by Ucn2 and Ucn3 in the presence vs absence of Astressin 2B dose 1 and in the presence vs the absence of Astressin 2B dose 2.


Estimated Enrollment: 12
Study Start Date: August 2010
Estimated Study Completion Date: August 2012
Estimated Primary Completion Date: August 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: Saline Placebo
In this arm, the response in forearm blood flow to incremental doses of Urocortins 2, 3 and Substance P will be studied co infused with saline placebo.
Drug: Saline placebo

After 20 minutes of intra arterial saline infusion, incremental doses of Urocortin 2, 3 and Substance P will be administered (in doses similar to Active comparator arm), co infused with saline placebo.

Bilateral venous blood samples will be taken at baseline, immediately before the start of Ucn2/Ucn3 infusion and at the end of each dose of Ucn2/Ucn3 for subsequent calculation of net release of t-PA and PAI-1.

Other Name: Forearm vascular study - Bilateral forearm blood flow will be measured at baseline and after each dose of Ucn 2, 3 and Substance P.
Active Comparator: Response to Urocortin infusion in presence of Astressin 2B
This arm studies the response to intra arterial infusion of incremental doses of Urocortins 2, 3 and Substance P in the presence or absence of a selective antagonist - Astressin 2B.
Drug: Urocortin 2, Urocortin 3

After a 20 minute infusion of intra arterial saline, healthy volunteers will receive ascending doses of intra arterial Urocortin 2 (3.4, 34 and 340 pmol/min to achieve estimated end-organ concentrations of 0.06, 0.6 and 6 µg/L, respectively), Urocortin 3 (3.4, 34 and 340 pmol/min to achieve estimated end-organ concentrations of 0.06, 0.6 and 6 µg/L, respectively) and Substance P (a control endothelium-dependent vasodilator that evokes endogenous t-PA release [2, 4 and 8 pmol/min]). This will be co-infused with either Astressin 2B (in one of the two doses determined from Protocol 1) or saline placebo.

Bilateral venous blood sampling will be performed at baseline, immediately before the start and after each dose of Urocortin 2 and 3, to later estimate net release of tPA and PAI-1 and for plasma measurements of Urocortins 2 and 3.

Other Name: Forearm vascular study - Forearm blood flow will be measured using venous occlusion plethysmography at baseline and with each dose of Ucn 2, 3 and Substance P.

  Eligibility

Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Healthy male volunteers between 18 - 65 years (inclusive)

Exclusion Criteria:

  • Lack of informed consent- Age <18 years > 65 years
  • Current involvement in a clinical trial
  • Severe or significant co-morbidity including bleeding diathesis, renal or hepatic failure
  • Smoker
  • History of anaemia
  • Recent infective/inflammatory condition
  • Recent blood donation (prior 3 months)
  • Positive baseline urine test for drugs of abuse (including cannabinoids, benzodiazepines, opiates, cocaine and amphetamines)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01096693

Locations
United Kingdom
Wellcome Trust Clinical Research Facility, Royal Infirmary of Edinburgh
Edinburgh, Mid Lothian, United Kingdom, EH16 4SA
Sponsors and Collaborators
University of Edinburgh
NHS Lothian
Investigators
Principal Investigator: David E Newby, PhD FRCP University of Edinburgh
  More Information

No publications provided

Responsible Party: University of Edinburgh
ClinicalTrials.gov Identifier: NCT01096693     History of Changes
Other Study ID Numbers: SV.Procotol 2
Study First Received: March 30, 2010
Last Updated: May 10, 2012
Health Authority: United Kingdom: Research Ethics Committee

Keywords provided by University of Edinburgh:
Urocortin 2
Urocortin 3
Astressin 2B
forearm blood flow
plethysmography
vascular
heart failure

Additional relevant MeSH terms:
Heart Diseases
Vascular Diseases
Cardiovascular Diseases
Substance P
Astressin
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Physiological Effects of Drugs
Neuroprotective Agents
Protective Agents
Central Nervous System Agents
Therapeutic Uses

ClinicalTrials.gov processed this record on August 21, 2014