Neurovascular Regulation During Exercise in Humans With Chronic Kidney Disease: Sympatholysis in CKD

This study investigates how the nervous system regulates blood flow to muscles during exercise in people with chronic kidney disease, comparing them to kidney transplant recipients and healthy controls to better understand exercise-related blood flow changes. **You may be eligible if...** - You have moderate-to-severe chronic kidney disease (CKD stage III or IV), or you have received a kidney transplant, or you are a healthy volunteer with normal kidney function - You have high blood pressure - You do not exercise regularly (less than 20 minutes twice a week) **You may NOT be eligible if...** - Your kidney disease is very severe (eGFR below 15) - You have heart failure, a history of heart attack or stroke in the past 6 months - You have diabetic nerve damage or autonomic dysfunction - You are severely anemic (hemoglobin below 10 g/dL) - You take certain blood pressure medications (central alpha-agonists like clonidine) - You have a pacemaker, metal implants, or claustrophobia (as an MRI is required) - You are pregnant or planning to become pregnant - You cannot ride a stationary bicycle Talk to your doctor to see if this trial is right for you.