Absorption of Water and Sodium from the Small Intestine of Patients with Nontropical Sprue

Abstract

There is evidence that the absorption of water from the gastrointestinal tract of patients with nontropical sprue is delayed when they have recently eaten food (1) and also when they have fasted (2, 3). Excessive fecal loss of sodium has been demonstrated in patients with nontropical sprue (4), and recently evidence obtained by the use of isotopic sodium has indicated that the absorption of sodium chloride from the small bowel of patients with this disease is delayed (5).The present study was undertaken to confirm, if possible, the presence of a defect in the absorption of water or sodium in fasting patients with nontropical sprue and to obtain a more exact measurement of its degree. The study was made possible by the recent development of a method that allows the precise quantitative determination of the rate of absorption of isotopically labeled substances from the gastrointestinal tract of human beings under completely physiologic conditions (6). METHODSFourteen patients who presented typical clinical, laboratory and roentgenographic features of nontropical sprue were studied. Three were men and 11 were women. Their ages ranged from 23 to 63 years with the majority being in the mid-thirties. Rates of absorption were determined in most of the patients on only one occasion, the majority of these being obtained during relapses of the disease. Six tests were made during remissions.A designation of the clinical status of the disease in each patient at the time the tests were performed has been used. When loss of weight, abdominal discomfort and diarrhea or any combination of such features of the disease predominated, the patient's clinical status was termed a "relapse." When such features were absent, or nearly so, the term "remission" has been used. The tests made in the course of this study fall into two groups. In the first, the rate of absorption of water alone was measured; eight such observations were made on five patients. In the second group, the rates of absorption of both water and sodium were determined. In addition to the dual determinations, refinements in methodology developed during the progress of the second part of the study allowed more precise determination of the rates of absorption of both water and sodium.The method (6) employed for estimation of the rate of absorption of a labeled substance requires determination of its rate of appearance in the arterial blood while it is being absorbed, as well as its rate of disappearance from the arterial blood stream after its rapid intravenous injection. The precise rate of absorption of the isotope is then calculated by integration of these two rates. In the past it has been necessary to employ mean rates of arterial disappearance of the isotopes as determined in a group of healthy persons (6)(7)(8), and this was the procedure adopted in the first group of observations presented in this report. While use of a mean rate of arterial disappearance has been appropriate for the study of normal human beings, since rates of arterial disappearance vary so litt...

Absorption of Radioactive Sodium From the Intestinal Tract of Man. I. Effect of Intestinal Motility. Ii. Effect of an Organomercurial*†

“…Particularly in patients in whom two control absorption and motility studies were performed, there was a parallel relationship between increased or decreased absorption and corresponding increase or decrease in segmental motor activity. However, the finding of normal rates of sodium transport in the presence of little intestinal motor activity of any type suggests that motility may not be as crucial a factor in the absorption of sodium from a saline medium as has been postulated (3,4). It is quite possible that intestinal motor activity may be of greater importance to the efflux of sodium from the lumen when the administered sodium is mixed with a more viscous substance such as food.…”

“…In 22 control tests, the unidirectional transfer of 50 per cent of the test dose of isotopic sodium occurred in a mean of 4.3 minutes as compared with a mean of 6.1 minutes in 13 normal patients studied elsewhere (3,4,14). Although it is possible that the absorption of greater than 100 per cent of administered sodium24 in seven patients represented re-excretion of sodium24 into the intestinal lumen, it is more likely that the errors of the method largely accounted-for this finding.…”

“…The technique of using a patient as his own control has been useful in the present studies on the effect of motility and organomercurial administration upon the transport of sodium from the intestinal lumen to arterial blood. 4. Intestinal motility as reflected by jejunal intraluminal pressure was simultaneously recorded in 15 control tests of sodium24 absorption.…”

“…The significance of intestinal motility in man has recently been evaluated (3,4). In normal subjects, administration of methantheline bromide (Banthine) significantly reduced the rate of sodium absorption from the intestinal lumen (3).…”

“…The diminished transport of sodium was considered to be due to the concomitant reduction in intestinal motor activity. In patients with sprue in relapse, the rate at which sodium entered the circulating blood from the small bowel was also significantly reduced (4,5). The altered intestinal motor activity observed in this condition, as well as the presence of an enzymatic defect, was thought to play an important role in the abnormal sodium absorption (4).…”