(A) Box-and-whisker plots illustrating the effects of subtotal nephrectomy on the glomerular filtration rate (GFR; left side of graph), as measured by ml/min of inulin clearance, and tubular secretion (right side), as measured by the clearance of para-aminohippurate (PAH). Two weeks after STN surgery there was a significant reduction in both GFR (~50%; *P ≤ 0.05) and tubular secretion (~50%; *P ≤ 0.05) in the STN animals (white rectangles) compared with the sham-operated animals (gray rectangles). Box plots were generated using the functionalities of BoxPlotR (92) (5 animals were used for each experimental group; a 2-tailed Student’s t test was used to determine statistical significance; a P value less than 0.05 was considered significant). (B) Box-and-whisker plots of the changes in amino acid concentrations following STN. The plasma concentration of tryptophan was significantly reduced following STN. Additionally, there were significant reductions in the plasma ratios of arginine to citrulline (*P ≤ 0.05). Black cross in each box represent the mean; solid black center lines indicate the median; open circles represent the individual data points; box limits indicate the 25th and 75th percentiles as determined by R software; whiskers extend 1.5 times the interquartile range from the 25th and 75th percentiles; outliers are represented by dots (92) (5 measures of plasma concentration were used for each experimental group; a 2-tailed Student’s t test was used to determine statistical significance; a P value less than 0.05 was considered significant).