The Effects of Preconditioning on Intramuscular High-Energy Phosphate Levels During Ischemia

Not Applicable

• Conditions: Ischemia
• Interventions: Procedure: no preconditioning; Procedure: preconditioning

• Registration Number: NCT00883467
• Lead Sponsor: Medical University of Vienna

Brief Summary

Ischemia reperfusion injury may be reduced by ischemic preconditioning. This projects aims to show the effects of short and long time ischemic preconditioning (both sequences 3 x 5 minutes) during and after an ischemic period of 20 minutes in healthy subjects by functional MRI. Ischemia is produces by cuff inflation to a suprasystolic pressure on one tight. Signal is acquired from calf muscles.

A cross-over design of 4 to 8 study periods is used, 4 different study days with 2 different MR measurement methods (BOLD imaging and high energy phosphates) are planned.

Detailed Description

Not available

Study Timeline

• Study Start: 2008-05
• Status Verified: 2009-04
• Study First Submitted: 2009-04-16
• Study First Submitted QC: 2009-04-16
• Last Update Submitted: 2009-04-16
• Study First Posted: 2009-04-17
• Last Update Posted: 2009-04-17
• Primary Completion: 2009-06

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: Male
• Target Recruitment: 16

Inclusion Criteria

• Men aged between 18 and 45 years
• Nonsmoker for more than 3 months
• Body mass index between 18 and 25 kg/m2
• Normal findings in medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant

Exclusion Criteria

• Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study
• Evidence of hypertension, pathologic hyperglycemia, hyperlipidemia
• Treatment in the previous 3 weeks with any drug including over-the-counter drugs
• Symptoms of a clinically relevant illness in the 2 weeks before the first study day
• Blood donation during the previous 3 weeks
• Any metallic, electric, electronic or magnetic device or object not removable
• Claustrophobia

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
1	no preconditioning	baseline MR signal prior to, during and 30 minutes after an ischemic period of 20 minutes
2	no preconditioning	baseline MR signal prior to, during and 30 minutes after an ischemic period of 20 minutes with additional 5 minutes of cuff stenosis directly after cuff release
3	preconditioning	short time preconditioning, other details according arm 2
4	preconditioning	long time preconditioning, other details according arm 2

Primary Outcome Measures

Name	Time	Method
Change in cellular high energy phosphate levels and venous pH concentration for 31P MRS	during and 30 min after ischemia
Main outcome variables: Change in cellular oxygen saturation for BOLD MRI	during and 30 minutes after ischemia
Serum markers of myocellular injury (myoglobin, creatine-kinase)	prior to, directly and 24 hours after ischemia

Trial Locations

Locations (1)

Medical University of Vienna, Department of Clinical Pharmacology; 🇦🇹 Vienna, Austria