This research study is being done to study the effects, both good and bad, of calcineurin inhibitors and the drug Cozaar (losartan), on kidney function and kidney scarring following a liver transplant.

This study is a double-blinded, placebo controlled trial to help determine the pathogenesis of chronic renal dysfunction in patients undergoing liver transplantation. It will examine the renal function and renal morphology in patients on calcineurin inhibitors and the effects of Cozaar (losartan) following liver transplantation. Participants will have blood, urine and iothalamate clearance test, to look at kidney function prior to transplant. At the time of transplant, kidney biopsies will be performed in the operating room under anesthesia. Participants will be in the study for one year. At three weeks following liver transplant, participants will be randomly assigned to receive either a placebo (inactive drug) or the study drug (losartan). The participant will need to continue to return to the clinic at the normal scheduled intervals. During these times blood and urine tests will be done. A kidney biopsy will be performed at the yearly exam and study pills will be stopped. The researchers will continue to follow participant's creatine measurements for the next 10 years.

Participants who will be undergoing a liver transplant and are between the ages of 18 to 70 years of age.