Net Chloride Absorption Research Articles

Salt and water absorption from the normal human colon: effect of 9-alpha-fluorohydrocortisone administration.

Abstract The entire colon of 31 healthy unanesthesized subjects was perfused at a rate of 10 ml. per minute via a preorally introduced polyvinyl tube located in the cecum. The test solution consisted of 0.85 per cent NaCl containing a nonabsorbable marker, polyethylene glycol (PEG), in the concentration of 0.5 per cent. Absorption and secretion of Na + , K + , Cl − , H 2 O, and HCO 3 − from and into the test solution were measured after it traversed the colon. In addition, unidirectional fluxes of H 2 3 O, Na 24 , K 42 from and into the colonic lumen were also determined in some experiments. The colon absorbed (mean ± S. D.) 2.11 ± 1.5 ml. per minute of H 2 O, 0.38 ± 0.24 mEq. per minute of sodium, and 0.57 ± 0.27 mEq. per minute of chloride from the test solution. At the same time, 0.03 ± 0.03 mEq. per minute of potassium and 0.15 ± 0.07 mEq. per minute of HCO 3 − were added to the test solution. Unidirectional fluxes of H 2 O, Na + , and K + were: (a) H 2 O flux out, 7.38 ± 1.6 ml. per minute; flux in, 5.6 ± 1.6 mEq. per minute; (b) sodium flux out, 0.51 ± 0.26 mEq. per minute; flux in, 0.28 ± 0.51 mEq. per minute; (c) potassium flux out, 0.020 ± 0.009 mEq. per minute; flux in, 0.051 ± 0.02 mEq. per minute. Twenty-four hours after intravenous administration of 2 mg. of 9-alpha-fluorohydrocortisone to 5 normal subjects, in the recumbent position, on a daily intake of 9.0 Gm. of salt, a significant increase in net absorption of sodium, chloride, and water from the test solution was found in all experiments (p

Studies on infant diarrhea. II. Absorption of glucose and net fluxes of water and sodium chloride in a segment of the jejunum.

10 infants with acute diarrhea passing liquid stools were chosen for this study of electrolyte and glucose absorption and net water fluxes in a jejunal segment. Electrolyte and glucose solutions of varying concentrations were perfused through a 25-cm segment of proximal jejunum in normal infants and in those with diarrhea. Under equilibrium conditions net fluxes of water glucose and electrolytes were determined. Diarrhea patients had impaired glucose absorption (159 mcmol per minute) vs. control infants (351 mcmol per minute). The net flux of water and salt was dependent on the proportion of glucose absorbed. Thus when the amount of nonabsorbed glucose was high water and salt moved into the bowel. However in the absence of glucose there was minimal net absorption of water and sodium chloride in both patients and controls. The net flux of water and sodium chloride into the jejunum seems to be determined by the effective osmotic pressure exerted by unabsorbed solute. These studies demonstrate that the absorption of glucose by the jejunum is impaired in acute diarrhea of infancy; these studies also show that the associated net movement of fluid into the bowel in diarrhea occurs as a consequence of bulk flow determined by excesses of glucose in the bowel lumen.

Net absorption of water, chloride and hexose from the intestine of dogs

Hexose and/or NaCl solutions were perfused at about 100 cm H2O pressure through small intestinal loops in unanesthetized dogs. The rate of glucose absorption increased in curvilinear fashion as the glucose concentration of the infusate ranged from 1% to 30% and did not differ between jejunal and ileal loops. Net chloride secretion rates were independent of perfusate hexose concentrations and were greater for jejunal than for ileal loops when nonchloride solutions were infused. Net chloride absorption rates increased with infusate concentrations ranging from 0.2% to 1.8% NaCl, and were greater for ileal than for jejunal loops. However, this difference may be due to the greater chloride secretion of jejunal loops. The curvilinear relationship between moles of glucose or chloride absorbed and lumen concentrations of these substances was rectified by plotting absorption rates against log concentration. The resulting Δ mm absorbed per hour/Δ log mm per liter concentration of the perfusate averaged 10.1 and 8.7 for chloride and glucose, respectively, in 6 dogs. Net fluid absorption rate decreased in curvilinear fashion with increasing perfusate osmolar concentration when NaCl or hexose was given. Net fluid absorption at given osmolar perfusate concentrations was greater from NaCl than from glucose or sorbose solutions.