The Effect of Hypertension Medications on Renal Blood Flow Measurements in Healthy Males (MK-0000-127)

A Randomized, Double-Blind, Placebo-Controlled, 4-Treatment, 3-Period, Incomplete Block, Balanced Crossover Study to Evaluate the Effects of a Single Dose of Aliskiren and Losartan on Renal Blood Flow Measurements in Healthy Male Subjects

This study will evaluate the effect of Aliskiren and Losartan on renal blood flow using PAH clearance, PC MRA and ASL MRI methodologies.

Inclusion Criteria:

• Subject is in generally good health
• Subject is willing to avoid unaccustomed strenuous exercise during the study
• Subject agrees to consume ONLY the study-specified diet during all domiciled periods
• Subject has been a non-smoker for at least 3 months prior to study
• Subject will refrain from smoking or using any tobacco products during the study
• Subject agrees to refrain from consuming alcohol or caffeine during the domiciled periods and agrees to limit alcohol and caffeine consumption throughout the study

Exclusion Criteria:

• Subject has contraindication to MRI scans
• Subject has a history of stroke, seizure, or major neurological disorders
• Subject uses illicit drugs or has a history of drug/alcohol abuse
• Subject has had major surgery, has donated or lost 1 unit of blood, or has been in another investigational study in the last 4 weeks
• Subject has a history of multiple and/or severe allergies to drugs or food