Measurements of Renal Glucose Release
- John E. Gerich, MD
- General Clinical Research Center, Strong Memorial Hospital, University of Rochester Medical Center, Rochester, New York
I am responding to Dr. Weir’s query for more details concerning how we handled our raw data in our article “Role of the Human Kidney in Glucose Counterregulation” (1).
Due to high rates of renal blood flow, small arteriovenous differences, and analytical variation, physiologically impossible results such as negative or extremely high fractional extractions (FXs) are not uncommonly observed. These phenomena are not unique to renal experiments, but they can be observed also in splanchnic balance experiments (2).
Some investigators, when obtaining physiologically impossible negative renal glucose FXs, have chosen to consider them as zero; other investigators have accepted these data at face value, while others have repeated what they have considered to be erroneous measurements. The first approach seems reasonable, although it would …
