INTERPRETATION OF DISACCHARIDE-DEPENDENT ELECTRICAL POTENTIAL DIFFERENCES IN THE SMALL INTESTINE

1976 ◽  
Vol 26 (1) ◽  
pp. 79-92 ◽  
Author(s):  
Yutaka IGARASHI ◽  
Yoshitaka SAITO ◽  
Masayoshi HIMUKAI ◽  
Takeshi HOSHI
Keyword(s):  
Small Intestine ◽  
Electrical Potential

scholarly journals Relation between sodium concentration, electrical potential and transfer capacity of rat small intestine

1967 ◽  
Vol 192 (3) ◽  
pp. 647-655 ◽  
Author(s):  
R. J. C. Barry ◽  
Jacqueline Eggenton ◽  
D. H. Smyth ◽  
E. M. Wright
Keyword(s):  
Small Intestine ◽  
Electrical Potential ◽  
Sodium Concentration ◽  
Rat Small Intestine

scholarly journals Phosphate transport into brush-border membrane vesicles isolated from rat small intestine

1976 ◽  
Vol 160 (3) ◽  
pp. 467-474 ◽  
Author(s):  
W Berner ◽  
R Kinne ◽  
H Murer
Keyword(s):  
Small Intestine ◽  
Transport System ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Electrical Potential ◽  
Membrane Vesicles ◽  
Sodium Concentration ◽  
Phosphate Transport ◽  
Brush Border Membrane Vesicles ◽  
Rat Small Intestine

Uptake of Pi into brush-border membrane vesicles isolated from rat small intestine was investigated by a rapid filtration technique. The following results were obtained. 1. At pH 7.4 in the presence of a NaCl gradient across the membrane (sodium concentration in the medium higher than sodium concentration in the vesicles), phosphate was taken up by a saturable transport system, which was competitively inhibited by arsenate. Phosphate entered the same osmotically reactive space as D-glucose, which indicates that transport into the vesicles rather than binding to the membranes was determined. 2. The amount of phosphate taken up initially was increased about fourfold by lowering the pH from 7.4 to 6.0.3. When Na+ was replaced by K+, Rb+ or Cs+, the initial rate of uptake decreased at pH 7.4 but was not altered at pH 6.0.4. Experiments with different anions (SCN-,Cl-, SO42-) and with ionophores (valinomycin, monactin) showed that at pH 7.4 phosphate transport in the presence of a Na+ gradient is almost independent of the electrical potential across the vesicle membrane, whereas at pH 6.0 phosphate transport involves the transfer of negative charge. It is concluded that intestinal brush-border membranes contain a Na+/phosphate co-transport system, which catalyses under physiological conditions an electroneutral entry of Pi and Na+ into the intestinal epithelial cell. In contrast with the kidney, probably univalent phosphate and one Na+ ion instead of bivalent phosphate and two Na+ ions are transported together.

scholarly journals Ionic Determinants of Electrical Potential in the In Vivo Small Intestine

1970 ◽  
Vol 58 (3) ◽  
pp. 363-370 ◽  
Author(s):  
Arthur C. Brown ◽  
Robert L. Vick ◽  
Eugene D. Jacobson
Keyword(s):  
Small Intestine ◽  
Electrical Potential

ADRENAL STEROIDS AND THE ELECTRICAL POTENTIAL OF RAT SMALL INTESTINE IN VIVO

1971 ◽  
Vol 49 (3) ◽  
pp. 377-386 ◽  
Author(s):  
H. M. NOBLE ◽  
A. J. MATTY
Keyword(s):  
Small Intestine ◽  
Short Circuit ◽  
Electrical Potential ◽  
Short Circuit Current ◽  
Electrical Potential Difference ◽  
Adrenal Steroids ◽  
Rat Small Intestine ◽  
Intestinal Activity ◽  
A New Technique

SUMMARY Using a new technique for determining transmucosal electrical potential difference (p.d.) and short-circuit current (Isc.) in the rat small intestine in vivo it would appear that aldosterone had no direct effect on these parameters of intestinal activity. However, adrenalectomy decreased the Isc. while after adrenalectomy aldosterone and cortisol (hydrocortisone) restored the lowered independent and probably also the lowered dependent (hexose) Isc.

Transport of monovalent cations by the isolated small intestine of the rat

1960 ◽  
Vol 199 (5) ◽  
pp. 898-906 ◽  
Author(s):  
T. W. Clarkson ◽  
A. Rothstein
Keyword(s):  
Small Intestine ◽  
Water Movement ◽  
Electrical Potential ◽  
Electrical Potential Difference ◽  
Monovalent Cations ◽  
Electrochemical Gradient ◽  
Cation Composition ◽  
Low Concentrations ◽  
The Media ◽  
Set Up

Everted segments of the small intestine of the rat, taken from both jejunal and ileal regions, were able to transport sodium against an electrochemical gradient by a highly specific mechanism. Other monovalent cations (cesium, potassium, lithium and triethylammonium) moved across the tissue much more slowly than sodium and always in the direction of the electrochemical gradient. Water movement appeared to be passive following the osmotic forces set up by active solute transfer. Both the electrical potential difference across the tissue and the net water transfer fell rapidly when the sodium concentrations in the media were reduced below 120 mm/l. Glucose transport was also responsive to the cation composition of the media; low concentrations of sodium were inhibitory, lithium at 25 mm/l. produced a stimulatory effect, and potassium at 25 mm/l. was inhibitory.

Sugar-stimulated ion absorption is not different in seahare and vertebrate intestine

1988 ◽  
Vol 255 (4) ◽  
pp. R583-R590
Author(s):  
W. M. Moran ◽  
L. T. Garretson
Keyword(s):  
Small Intestine ◽  
Apical Membrane ◽  
Short Circuit ◽  
Electrical Potential ◽  
Short Circuit Current ◽  
Electrical Potential Difference ◽  
Histological Findings ◽  
Ion Absorption ◽  
Ion Substitution ◽  
Membrane Electrical Potential

We have reexamined the notion that sugars stimulate ion absorption differently in invertebrate and vertebrate intestine. In the seahare intestine, mucosal sugar presumably increases the rate of transcellular Na+ and Cl- absorption, whereas only transcellular Na+ absorption is increased in the vertebrate small intestine. Our data indicate that the seahare intestine responds to mucosal D-galactose like the vertebrate small intestine: namely, the apical membrane electrical potential difference depolarizes, the ratio of the mucosal to serosal membrane resistances decreases, and the short-circuit current (Isc) increases. Because mucosal substitution of tetramethylammonium for Na+ abolished the increased Isc, this stimulation resulted from an increase in rheogenic Na+ absorption. Unidirectional transepithelial Cl- fluxes indicate that mucosal D-galactose had no effect on the net Cl- flux under short-circuit conditions. Further, ion substitution experiments indicate that the apical membrane is K+ conductive rather than Cl- conductive as previously reported. These electrophysiological as well as parallel histological findings indicate that studies previously reported on the seahare intestine were in fact conducted on the esophagus.

Interpretation of Hexose-dependent Electrical Potential Differences in Small Intestine

Nature ◽  
1967 ◽  
Vol 214 (5087) ◽  
pp. 509-510 ◽  
Author(s):  
STANLEY G. SCHULTZ ◽  
PETER F. CURRAN ◽  
ERNEST M. WRIGHT
Keyword(s):  
Small Intestine ◽  
Electrical Potential
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