Study design. Twelve wk old male AT1a receptor knockout (AT1a-KO) mice were injected with either 0.1 M citrate buffer (pH 4.5) or streptozotocin (50 mg/kg) for five days. After 2 wks, animals with blood glucose levels of ≥ 250 mg/dl were considered diabetic. Echocardiographic measurements were taken in all groups at the beginning (Before STZ), onset of diabetes (0 wk), and at two wk intervals thereafter. Osmotic minipumps containing one of the drugs were implanted subcutaneously at 0 wk and replaced after 4 and 8 wks. At the conclusion of the study (10 wks), blood pressure was measured by carotid artery cannulation and tissues were collected.