Experimentally-induced acute heat and pressure pain in young, healthy participants.
Conditions
Interventions
Group 1: Naloxon (Firma Ratiopharm) 0,4 mg/ml Injectable Solution
In the present study, an intravenous bolus dose of 0,15mg/kg will be injected. Due to the short half lifet (ca. 70 minutes in blood p
Sponsors
Universitätsklinikum Hamburg-Eppendorf Institut für systemische Neurowissenschaften
Eligibility
Sex/Gender
All
Age
18 Years to 45 Years
Inclusion criteria
Inclusion criteria: - Healthy, young volunteers between the age of 18 and 45. - Legal capacity to sign consent information sheet and rate reliably. - BMI between 18 and 30. - Right-handedness
Exclusion criteria
Exclusion criteria: - Acute or chronic pain (including muscle aches) - Acute or chronic somatic or psychologically relevant illnesses (based on diagnosis or self report) - MR-specific exclusion criteria (e.g. Claustrophobia, non MR-compatible metal foreign bodies) - Participation in pharmacological studies or regular intake of pharmacological substances (except oral contraceptives, alllergy medication, irregular use of pain killers or thyroid medication) - Intake of pain killers 24h prior to study - Needle/Blood fear - Pregnant or nursing - acute dermatological disease or injury in relevant places (arm) - acute symptoms of respiratory disease (e.g. stress asthma) - previous or acute opioid addiction - regular drug consumption - cardiovascular diseases (e.g. Angina Pectoris) - Disease of Immunesystem - Diease of nervous system - Disease of the gastrointestinal tract - Taking of cardiotoxic medicine/substance (e.g. Cocaine, Metamphetamine, cyclic Antidepressants, Calcium antagonists, Betablocker, Digoxin
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| 1) What is the primary outcome of the study? Exercise-induced Hypoalgesia refers to the phenomenen of attenuated pain perception following acute exercise. This study aims to contribute to the understanding of this effect for different nociceptive stimuli (pressure and heat pain) on a behavioural, physiologcal and (sub-)cortical level. Furthermore, this study aims to investigate potential pharmacolocial mechanisms (endogenous opioid system and endocannabinoid system) underlying this effect. 2) How will this outcome be achieved? In order to induce exercise-induced hypoalgesia, subjects will cycle in 4 blocks for 10 minutes at high (2 blocks) and low (2 blocks) intensity (individually calibrated). Following each block, subjects will be transferred to the MR scanner and receive alternating pressure and heat stimuli above their pain threshold. They will be asked to rate each stimulis in its painfulness ranging from 0 [minimally painful] to 100 [unbearably painful]. Blood samples will be collected follwoing each exercise block. Furthermore, subjects will receive either naloxone or NaCl in a randomised crossover design. 3) Which parameters will be measured to achieve the primary outcome? Behavioural data (pain ratings), physiological data (blood pressure, pulse, oxygen saturation, respiration, blood samples) and fMRI data (brain activation as changes in BOLD signal) will be measured, in order to draw a valid conclusion on the existence and intenstiy of an exercise-induced hypoalgesic effect. In addition, subejcts will receive naloxone (experimental condition) and isotonic saline solution (control condition) in a crossover design. Based on this, potential involvement of the endogenous opioid system in exercise-induced hypoalgesia shall be identified. 4) What will be analysied in order to achieve primary outcome? In order to identify if and to what extent an exericse-induced hypoalgesic effect follows acute aerobic exercise, pain ratings for heat and pressure pain | — |
Secondary
| Measure | Time frame |
|---|---|
| Differenct questionnaires will be included into analyses, such as a questionnaire for mood and depression. Furthermore, blood samples will be drawn after each exercise block in order to identitfy potential changes in cytokines and endocannabinoids. This will enable us to pinpoint possible interactions between exercise-induced hypoalgesia and changes in blood parameters. | — |
Countries
Germany
Contacts
Public ContactJanne Nold
Universitätsklinikum Hamburg-Eppendorf Institut für systemische Neurowissenchaften
Outcome results
None listed