Simultaneous measurements of arterial NH4+ concentration, urinary NH4+ excretion, net-acid excretion and the bidirectional release of NH4+ by the kidney have been made in 11 patients with chronic bronchitis in order to determine the influence of changes in arterial gas tensions and/or pH on the renal release of NH4+. The present findings suggest that in this clinical situation both the urinary excretion and the bidirectional release of NH4+ by the kidney is related to the arterial carbon dioxide tension. Although elevated values for arterial NH4+ concentration were found in some patients with respiratory failure this could not be accounted for by an increase in the release of NH4+ into the renal vein. Increasing the concentration of inspired oxygen resulted in a reduction in the urinary excretion of both NH4+ and net-acid and a decrease in the release of NH4+ into the renal vein, despite a marked increase in the extracellular hydrogen ion concentration. The influence of acute changes in renal blood flow on NH4+ release by the kidney is discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.