Effect Camostat for Kidney Protection in Chronic Kidney Disease

This clinical trial aims to evaluate the effects of Camostat Mesylate, a serine protease inhibitor, in patients with chronic kidney disease (CKD) and proteinuria. Proteinuria accelerates CKD progression and increases cardiovascular risks. By inhibiting serine protease activity and tubular complement activation, camostat may mitigate progressive kidney injury, potentially improving clinical outcomes. This is an interventional, non-randomized, open-label pharmacodynamic trial that includes CKD patients with proteinuria and healthy controls. This approach has been chosen as the trial serves as a pilot study, aiming to investigate a novel treatment target in CKD patients. Including healthy controls allows a comparison of the effect of Camostat Mesilate on normal physiology versus CKD with proteinuria. Participants will: * Follow a standardized sodium diet of 150 mmol/day for 8 days. * Receive oral Camostat Mesilate (200 mg thrice daily) for four days (day 5-8 on the diet). * Provide blood and urine samples, record blood pressure, and undergo body composition measurements at baseline, during intervention, and at study completion. The primary effect parameters are urine sodium and water excretion, body water content/weight, and home blood pressure. Secondary endpoints are tubular complement activation, urine protease activity, ENaC activation, 24-hour urine albumin excretion, and plasma concentrations of renin, angiotensin II, aldosterone, and NT-proBNP.