Secretion and reabsorption of bicarbonate in single renal tubules of the rabbit.

Bicarbonate is transported by a number of different renal tubule segments. Both the rates of transport and the mechanisms involved differ between the segments. Although bicarbonate is absorbed by both proximal tubules and collecting ducts, bicarbonate secretion has been observed only in the collecting ducts. Bicarbonate secretion in cortical collecting ducts, bicarbonate secretion has been observed only in the collecting ducts. Bicarbonate secretion in cortical collecting ducts results from conditioning of that tubule segment, following administration of alkali to the animals.