Final answer:
PTT (Partial Thromboplastin Time) is not an indication of renal function; instead, it measures blood clotting time. BUN and creatinine are both used to assess kidney health.
Step-by-step explanation:
The test that is NOT an indication of renal function among the options given is PTT (Partial Thromboplastin Time). Blood urea nitrogen (BUN) and creatinine levels in the blood are both used to assess renal functions. These tests evaluate the kidney's ability to filter and remove waste products from the blood. BUN is an estimate of urea in the blood, whereas creatinine is a waste product of muscle metabolism that is filtered by the kidneys. In comparison, PTT is a blood test that measures the time it takes for blood to clot and is used to assess the blood's clotting ability, not kidney function.