Interaction Between NGF and Acute Exercise-induced Ischemia

Study Overview
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Brief Summary
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The purpose of this study is to investigate pain evoked responses and facilitation of NGF-induced mechanical muscle hyperalgesia over time following an acute exercised-induced ischemic condition in a NGF-sensitized muscle.

Detailed Description
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Assessing evoked pain responses and muscle hyperalgesia following contractions during acute ischemia in a NGF-sensitized muscle may clarify whether an interaction between NGF sensitization and acidic stimulation exist. It is hypothesized that acute ischemic exercise with the NGF-sensitized TA muscle, in contrast to ischemic exercise in a non-sensitized would: 1) potentiate pain-evoked responses, and 2) facilitate NGF-induced muscle hyperalgesia.

Official Title
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The Interaction Between NGF-induced Muscle Sensitivity and Acute Exercise-induced Ischemia

Conditions
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Hyperalgesia, Pain Response, Healthy Subjects

Intervention / Treatment
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* Drug: NGF
* Drug: Isotonic saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy and pain free volunteers Exclusion Criteria: Pregnancy Drug addiction defined as the use of cannabis, opioids or other drugs Previous neurologic, mental illnesses, or psychiatric diseases. Past history of chronic pain in the musculoskeletal system (muscle, joint, cartilage, connective tissue) Participation in other pain trials throughout the study period Lack of ability to cooperate Taking any analgesic 24 hours before the injections Performing any strenuous leg exercise through out the study period causing sore muscles

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: NGF condition + Control condition<br>All participants will receive five injections with NGF (1ug/0.5ml) into the tibialis anterior muscle in their non-dominant leg After 4 weeks: All participants will receive five injections with isotonic saline (9%/0.5ml) into the tibialis anterior muscle in their non-dominant leg | Drug: NGF<br>* Intramuscular injection<br>* Other names: Beta-Nerve Growth Factor, Human;Drug: Isotonic saline<br>* Intramuscular injection<br>* Other names: Control;|
| Experimental: Control condition + NGF condition<br>All participants will receive five injections with isotonic saline (9%/0.5ml) into the tibialis anterior muscle in their non-dominant leg After 4 weeks: All participants will receive five injections with NGF (1ug/0.5ml) into the tibialis anterior muscle in their non-dominant leg | Drug: NGF<br>* Intramuscular injection<br>* Other names: Beta-Nerve Growth Factor, Human;Drug: Isotonic saline<br>* Intramuscular injection<br>* Other names: Control;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle sensitivity | Pressure pain thresholds (PPTs) are assessed over the non-dominant tibialis anterior muscle using a handhold pressure algometer. | Change from baseline at 1 week | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ischemic-induced pain intensity | Subjects perform 45 dorsiflexions with their non-dominant leg while a cuff is mounted over the knee to occlude the blodflow from the muscle (ischemia) Subjects subsequently rate their perceived pain intensity verbally on a numeric rating scale (NRS) | Assessed right after the dorsiflexions have been performed | 
| Functional muscle pain | Subjects evaluate their muscle pain during movement using a Likert Scale for lower limp | Change from baseline at 1 week | 
| Muscle pain diary | Subjects evaluate their muscle pain during movement using a Likert Scale for lower limp and perceived pain intensity at rest on a numeric rating scale (NRS). The diary is filled out at home on days between sessions | Change from baseline at 1 week | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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NGF-induced pain, Ischemia-induced pain, Hyperalgesia, NGF pain model