What is the transpo maximum for glucose?
Glucose, amino acids, and bicarbonate are reabsorbed along with Na+ in the early poion of the proximal tubule. Faher along the tubule, Na+ is reabsorbed with Cl-. Glucose is typical of substances removed from the urine by secondary active transpo. It is filtered at a rate of approximately 100 mg/min (80 mg/dL of plasma x 125 mL/min). Essentially all of the glucose is reabsorbed, and no more than a few milligrams appear in the urine per 24 h. The amount reabsorbed is propoional to the amount filtered and hence to the plasma glucose level (PG) times the GFR up to the transpo maximum (TmG). When the TmG is exceeded, the amount of glucose in the urine rises. The TmG is about 375 mg/min in men and 300 mg/min in women. Ref: Ganong's Review of Medical Physiology 23rd edition, Chapter 38.
175 mg/min
275 mg/min
375 mg/min
475 mg/min