Estimation of Total Body Sodium by Isotopic Dilution. Ii. Studies on Infants and Children: An Example of a Constant Differential Growth Ratio 12

An Appraisal of Methods of Tissue Chloride Analysis: The Total Carcass Chloride, Exchangeable Chloride, Potassium and Water of the Rat 1

“…Fat is a variable quantity in the body and it is not possible to compare accurately data obtained from one animal with those from another unless the results are expressed in terms of lean body mass or fat free, dry solid. In Table VI Many workers in presenting data on total body electrolyte have followed the principles established by Needham (31) and have plotted total electrolyte on a double logarithmic grid using body weight as a standard of reference (11,19,32,33). Such plots are of value in that they emphasize the exponential nature of growth.…”

“…Such plots are of value in that they emphasize the exponential nature of growth. It has been shown that from early life to maturity, chemical growth with respect to chloride and sodium can be expressed by a simple exponential function (11,32). When data for total electrolyte (34) are plotted against body weight on an arithmetic grid, considerable scatter is evident whereas in double logarithmic plots the scatter is not conspicuous.…”

GASTROINTESTINAL WATER AND ELECTROLYTES. II. THE EQUILIBRATION OF RADIOPOTASSIUM IN GASTROINTESTINAL CONTENTS AND THE PROPORTION OF EXCHANGEABLE POTASSIUM (Ke) IN THE GASTROINTESTINAL TRACT 1

“…of body weight, or 0.14 per cent of the predicted Ke. In man studied postmortem the distribution of gut potassium differs from the distribution of gut sodium, in that the cecum and proximal transverse colon contain about 43 per cent of gut potassium as against 22 per cent of gut sodium, while the stomach contains 14 per cent of gut potassium compared to 28 per cent of gut sodium (4). DISCUSSION The concentration of potassium in the gastrointestinal contents is almost always greater than that in plasma.…”

“…At the time of radioassay the resultant mixture of K' (half-life, 12.4 hours) and K" (half-life, 22 collected for assay of radioactivity and chemical analyses cate dilutions of the separate gastrointestinal contents as described in the first paper in this series (4). In using a lithium internal standard flame photometer.…”

Gastrointestinal Water and Electrolytes. III. The Equilibration of Radiobromide in Gastrointestinal Contents and the Proportion of Exchangeable Chloride (Cle) in the Gastrointestinal Tract1

“…Infants have significantly more chloride, averaging 51 mEq. per kgm., which is to be expected in view of their higher body sodium and water contents (13,24,25). Weir (7) estimated the Cl8 in rabbits to be 30 mEq.…”