Biased GRK Signaling Via β2-Adrenergic Receptors in Human Skeletal Muscle

Starting soon · Phase 2

Conditions studied: Overweight and Obesity

In brief

This longitudinal mechanistic physiological study examines biased β2-adrenergic receptor (β2-AR) signaling in human skeletal muscle, with emphasis on G protein-coupled receptor kinase (GRK)-mediated pathways. Participants will receive daily oral dosing of the GRK-selective long-acting β2-agonist ATR-258 for 8 weeks. Muscle biopsies and physiological measurements will quantify GRK-, cAMP/PKA-, and β-arrestin-related signaling, fiber-type specificity, and potential receptor desensitization with repeated stimulation.

Key facts

Study ID

NCT07421024

Run by

Morten Hostrup, PhD

People needed

10

Starts

2026-02-20

Expected to finish

2026-12-31

Last updated by the study team

2026-02-19

Who can join

Age: 21 and older, up to 45. Sex: male. Healthy volunteers: accepted.

You may qualify if…

• Healthy men
• Age 21-45 years
• BMI 25-35 kg/m\^2
• Body fat percentage 25-40%
• Lean Mass Index 14-22

You may not qualify if…

• Regular use of or allergy to β2-agonists
• Serious adverse reactions to β2-agonists
• Current smoker
• Regular use of medication (except OTC allergy or analgesics)
• Abnormal ECG before or after β2-AR stimulation
• Hypertension
• Reduced kidney function (eGFR < 90 ml/min/1.73m\^2)
• Cardiovascular, metabolic, gastrointestinal, renal, or pulmonary disease
• Psychiatric or neurological disorders affecting compliance/safety reporting
• Cancer history within the last 5 years
• Substance abuse or alcohol intake >14 units/week

Where it is running

• University of Copenhagen, August Krogh Section for Human & Molecular Physiology — Copenhagen, Denmark

Full record on ClinicalTrials.gov

Trial information comes from ClinicalTrials.gov and is refreshed daily. TrialsForMe does not provide medical care and does not run the studies it lists.