CALCULATION OF INTRACELLULAR pH FROM THE DISTRIBUTION OF 5,5-DIMETHYL-2,4-OXAZOLIDINEDIONE (DMO). APPLICATION TO SKELETAL MUSCLE OF THE DOG*
Year: 1959
Type: article
Abstract: Estimations of hydrogen ion activities in the interior of cells have been attempted through a number of different experimental approaches. The methods that have been employed are of sev-eral general types: measurements on preparations of broken cells, measurements on fluid with-drawn from cells, observations with visible in-dicators, measurements with micro-electrodes introduced into cells, measurements of the intra-cellular and extracellular concentrations of weak organic acids and bases, and calculation of the balance of ionic charges. The last named method has been proposed by Conway (1). The other methods are discussed in the review of Caldwell (2), which contains a tabulation of the results of measurements on various types of cells with differ-ent experimental methods. Some of the methods that have been used are of quite limited applica-bility, and most of the values arrived at by any of the methods are subject to question. Potentially, the method utilizing the distribu-tion of weak organic acids and bases has a wider range of applicability than the other methods, and it is not subject to some of the theoretical objec-tions that can be raised to other methods. There is a great deal of evidence that membranes of ani-mal and plant cells in general are characterized by free permeability to the undissociated forms of weak organic acids and bases and by impermea-bility or apparent impermeability to the ionic forms. If the pH of the interior of a cell differs from that of the external medium in contact with it, there will be a corresponding difference in the concentration of an organic ion. The assumption * This investigation was supported in part by a re-search grant (B-384) from the National Institute of
DOI: 10.1172/jci103852
Authors: William J. Waddell, Thomas C. Butler
Institution: University of North Carolina at Chapel Hill
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2096120477