Angiotensin II human acetate is a key vasoconstrictor peptide in the renin-angiotensin system. It regulates blood pressure by binding to AT1R and AT2R receptors, stimulates the sympathetic nervous system, promotes aldosterone synthesis and renal function, induces vascular smooth muscle cell proliferation and collagen synthesis, leading to vascular and myocardial hypertrophy and fibrosis, while also promoting apoptosis and endothelial capillary formation. It is commonly used to induce hypertension and cardiac hypertrophy models.