Macrophage depletion led to reduced blood pressure in the hypertensive mice, decreased kidney Col1a1, Acta2, Col3a1 and Fn1. This study shows that renal macrophage infiltration and fibrosis begin early in hypertension development and depleting macrophages in hypertension reduces blood pressure and suppress renal fibrosis. This evidence concerns the gene COL1A1 and renal fibrosis.