ABSTRACT
Marked acidification takes place between the formation of glomerular filtrate and the formation of urine. Many parts of the nephron contribute to this acidification of the tubular fluid by either excreting H+ ions combined with HP042-or NH3, or by excreting fewer HCO3-ions. There are a number of different cellular mechanisms for excretion of acid, such as Na + /H + exchange or active pumping of H+ ions into the luminal fluid.
