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Purpose

This study is investigating changes to the proteins in skeletal muscle that contribute to reduced muscle size and muscle function that occurs with aging.

Conditions

Eligibility

Eligible Ages
Between 18 Years and 80 Years
Eligible Sex
All
Accepts Healthy Volunteers
Yes

Inclusion Criteria

  • Adults between the ages 18-35 or 65-80 years - Healthy by self-report - Willing to participate in all aspects of the study design including muscle biopsy, unilateral exercise, and physical activity monitoring - Fluent in English (due to lack of translation services, it is not practical to conduct the study using a language other than English).

Exclusion Criteria

  • Orthopaedic limitation (severe knee osteoarthritis, prior joint replacement, etc.). - Volunteer has dementia or related mental issues that potentially put the subject at risk as determined by prior diagnosis. - Volunteer has known untreated endocrine disease (hypo/hyper thyroidism, Addison's Disease or Cushing's syndrome, etc.) - Volunteer has untreated/poorly-controlled hypertension (stage 2, per American College of Cardiology [>140/90 mmHg]). - Volunteer has significant heart, liver, kidney or respiratory disease. - Volunteer has diabetes (insulin dependent or non-insulin dependent). - Volunteer has known coagulopathies. - Volunteer has taken anabolic steroids in the prior six months. - Volunteer has received treatment for cancer (other than effective Mohs Surgery for successful removal of basal cell or squamous cell carcinomas) - Unexpected weight loss >5kg is last 12 months - Volunteer is an active smoker or quit within the last year. - Volunteer has known current alcohol or drug use disorder (AUD; defined as binge drinking of >4 days in the last month. Binge drinking is >5 drinks for men and >4 drinks for women, per occasion). Or, if a volunteer reports drinking in excess of "low risk" per NIAAA (>7 drinks/week for men and >3 drinks/day for women and >14 drinks/week and >4 drinks/day). - Volunteer has a diagnosed neuromuscular disorder. - Volunteer has allergy to lidocaine.

Study Design

Phase
N/A
Study Type
Interventional
Allocation
N/A
Intervention Model
Single Group Assignment
Primary Purpose
Basic Science
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Fatigue 		Volunteers will perform one-legged knee extension exercise until fatigue while seated on an ergometer. Volunteers will then undergo bilateral skeletal muscle biopsies of the vastus lateralis muscle in their thigh.
  • Behavioral: Fatiguing Exercise
    Volunteers will perform knee extension exercise of the dominant limb while seated in a chair designed for exercise of the knee extensor muscle group. The chair will be equipped with a lever arm, aligned with the axis of rotation of the knee and fixed to the distal shank, 2 centimeters proximal to the ankle joint. The lever arm will be instrumented to provide resistance and measure velocity. The volunteers will perform 3-5 maximum voluntary contractions (MVC) to determine peak torque. Once established, volunteers will rest for 5 minutes before initiating the fatigue protocol, whereby they will perform repeated MVC of the dominant limb against resistance equal to or less than 50% of MVC until range of motion cannot be maintained. Because the goal of this exercise is to uniformly fatigue the quadriceps muscle group, this exercise will be performed continuously. It is expected to take between 1 and 3 minutes to achieve the desired level of fatigue.

Recruiting Locations

University of Oregon
Eugene, Oregon 97403
Contact:
Damien M Callahan, Ph.D.
458-205-5343
damienc@uoregon.edu

More Details

Status
Recruiting
Sponsor
University of Oregon

Study Contact

Damien M Callahan, Ph.D.
541-346-5040
damienc@uoregon.edu

Detailed Description

Age-related muscle atrophy and contractile dysfunction have been well described at the cellular level, but the molecular mechanisms that contribute to this dysfunction are poorly understood. Improved understanding of these mechanisms is critically important for the improvement of physical rehabilitation in older adults at risk for mobility impairment and physical disability. Our studies will pursue pre-clinical evidence that post translational modification of specific proteins in skeletal muscle lead to an "aging phenotype" in skeletal muscle that may unlock new strategies for improving physical function in older adults with physical frailty.

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.