an accurate measure of the rate of filtration through the renal glomeruli, because inulin filters freely with water and is neither excreted nor reabsorbed through tubule walls. Inulin is not a normal constituent of plasma and must be infused continously to maintain a steady plasma concentration and a steady rate of urinary excretion during the measurement. Inulin clearance in a normal adult person is about 120 mL/min (range, 100–150) per 1.73 m2 body surface area.
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Examples: glitazone, GI cocktail, etc.