 If the study visit occurs 3 weeks or more after the health screening, the female subjects will undergo a second, urine-based pregnancy test on the morning of the study visit. In addition, healthy women will be required to continue employing an accepted birth control method and not attempt to become pregnant for at least one month following completion of the final study visit. Women with CKD will be requested to continue employing an accepted birth control method for at least two months following completion of the final study visit. 