Role of Prostaglandins in the Regulation of Brain Blood Flow

NCT00006318 | Completed

• 2 other identifiers: 00022600-CC-0226
• Study Type: observational
• Target: 125
• Locations: 1 country
• Sites: 1

Brief Summary

This study will use magnetic resonance imaging (MRI) to examine the role of prostaglandins-a type of fatty acid with hormone-like actions-in the regulation of brain blood flow. The results will provide information on how to better use this technique to study brain function, which, in turn, may lead to a better understanding of certain illnesses and more effective treatments. Healthy normal volunteers 18 years of age and older may be eligible for this study. Participants will fill out a health questionnaire and undergo a history, physical examination and MRI studies. MRI is a diagnostic tool that uses a strong magnetic field and radio waves instead of X-rays to show structural and chemical changes in tissues. During the scanning, the subject lies on a table in a narrow cylinder containing a magnetic field. An intercom system allows the subject to speak with the staff member performing the study at all times during the procedure. Four separate studies will be done-two carbon dioxide inhalation studies and two functional activation studies-as follows: Carbon dioxide inhalation (indomethacin): This study is done in two parts. In both parts, an MRI brain scan is done. During the scan, the subject inhales an air mixture containing 6% carbon dioxide through a facemask or mouthpiece. Blood pressure and heart rate are monitored during inhalation of the mixture. For the second part of the study, indomethacin-a non-steroidal anti-inflammatory drug-is injected through a catheter (thin flexible tube) in an arm vein. Indomethacin inhibits prostaglandin production. Total scan time averages between 45 and 90 minutes, with a maximum of 2 hours. Carbon dioxide inhalation (rofecoxib and celecoxib): This study is identical to the one above, except either rofecoxib or celecoxib is given instead of indomethacin. Both of these drugs are also non-steroidal anti-inflammatory drugs that inhibit prostaglandin production. Unlike indomethacin, rofecoxib and celecoxib are given orally instead of through a vein, so, to allow time for the drug to be absorbed, the second scan is delayed for 2 hours. Functional activation (indomethacin): This study is done in two parts. In both parts, a MRI brain scan is done. During the study, the subject performs a simple motor task, such as finger tapping. For the second part of the study, indomethacin is injected through a catheter in an arm vein. Functional activation (rofecoxib and celecoxib): This study is identical to the indomethacin functional activation study, except either rofecoxib or celecoxib is given instead of indomethacin. Because they are given orally instead of through a vein, the second scan is delayed 2 hours to allow time for the drug to be absorbed.

Conditions

Healthy; Hypercapnia

Keywords

Cerebral Blood Flow; CO2 Inhalation; Imaging; MRI; Perfusion; Functional Activation

Eligibility Criteria

• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Any healthy normal volunteer above the age of 18 who is capable of giving informed consent.

You may not qualify if:

• Subjects will be excluded for the following reasons.
• They have contraindications to MR scanning, such as the following: aneurysm clip, implanted neural stimulator, implanted cardiac pacemaker or autodefibrillator, cochlear implant, ocular foreign body (e.g., metal shavings), or insulin pump.
• They have panic disorder or migraine (because of possible complications with CO2 inhalation).
• They have cirrhosis, any renal dysfunction, or a chronic respiratory illness (such as asthma).
• They have allergies to sulfonamide drugs or cyclo-oxygenase inhibitors (NSAIDS).

Sponsors & Collaborators

• National Institutes of Health Clinical Center (CC): lead

Study Sites (1)

Warren G. Magnuson Clinical Center (CC)

Bethesda, Maryland, 20892, United States

Location

Related Publications (3)

• O'Banion MK. Cyclooxygenase-2: molecular biology, pharmacology, and neurobiology. Crit Rev Neurobiol. 1999;13(1):45-82. doi: 10.1615/critrevneurobiol.v13.i1.30.

  PMID: 10223523 BACKGROUND

• Kaufmann WE, Worley PF, Pegg J, Bremer M, Isakson P. COX-2, a synaptically induced enzyme, is expressed by excitatory neurons at postsynaptic sites in rat cerebral cortex. Proc Natl Acad Sci U S A. 1996 Mar 19;93(6):2317-21. doi: 10.1073/pnas.93.6.2317.

  PMID: 8637870 BACKGROUND

• Yamagata K, Andreasson KI, Kaufmann WE, Barnes CA, Worley PF. Expression of a mitogen-inducible cyclooxygenase in brain neurons: regulation by synaptic activity and glucocorticoids. Neuron. 1993 Aug;11(2):371-86. doi: 10.1016/0896-6273(93)90192-t.

  PMID: 8352945 BACKGROUND

MeSH Terms

Conditions

Hypercapnia

Condition Hierarchy (Ancestors)

Signs and Symptoms, Respiratory; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: observational
• Sponsor Type: NIH

Study Record Dates

• First Submitted: September 30, 2000
• First Posted: October 2, 2000
• Study Start: September 1, 2000
• Study Completion: December 1, 2003
• Last Updated: March 4, 2008

Record last verified: 2003-12

Locations

US (1)