Losartan (180 mg/d) causes significant increases in plasma angiotensin II and angiotensin-(1-7) in monkeys with diet-induced hypercholesterolemia. Losartan (180 mg/d) reduces the extent of fatty streak in the aorta, the coronary arteries, and the carotid arteries by approximately 50% in monkeys with diet-induced hypercholesterolemia. Losartan reduces the susceptibility of LDL to in vitro oxidation, serum levels of monocyte chemoattractant protein-1, and circulating monocyte CD11b expression in monkeys with diet-induced hypercholesterolemia. ^[2] Losartan (0.6 g/L in their drinking water) prevents elastic fiber fragmentation and blunted TGF-β signaling in the aortic media in pregnant Fbn1^C1039G/+ mice, as evidenced by reduced nuclear accumulation of pSmad2. Losartan (0.6 g/L in their drinking water) shows a reduction in distal airspace caliber in pregnant Fbn1^C1039G/+ mice. Losartan (0.6 g/L in their drinking water) improves disease manifestations in the lungs, an event that cannot plausibly relate to improved hemodynamics in pregnant Fbn1^C1039G/+ mice. ^[3] Losartan (5 mg/kg/d) leads to a significant decrease in the development of atherosclerotic lesions in the apo E deficient mice. Losartan (5 mg/kg/d) significantly reduces the susceptibility of the mice LDL to lipid oxidation following its incubation with CuSO4 in the apo E deficient mice. ^[4] Losartan (10 mg/kg) administration increases blood angiotensin levels four fold to six fold, blood BK levels are unchanged in male Sprague Dawley rats. Losartan (10 mg/kg) increases plasma renin levels 100-fold, plasma angiotensinogen levels decreases to 24% of control and plasma aldosterone levels are unchanged in male Sprague Dawley rats. ^[5]