scholarly journals Effects of amiloride and ouabain on short-chain fatty acid transport in guinea-pig large intestine.

1993 ◽  
Vol 460 (1) ◽  
pp. 455-466 ◽  
Author(s):  
W von Engelhardt ◽  
M Burmester ◽  
K Hansen ◽  
G Becker ◽  
G Rechkemmer
2012 ◽  
Vol 37 (11) ◽  
pp. 2562-2568 ◽  
Author(s):  
Ivano Moschen ◽  
Angelika Bröer ◽  
Sandra Galić ◽  
Florian Lang ◽  
Stefan Bröer

1978 ◽  
Vol 74 (5) ◽  
pp. 1005 ◽  
Author(s):  
S. Bar-Meir ◽  
H. Ruppin ◽  
K.H. Soergel ◽  
S. Broor ◽  
C.M. Wood

1987 ◽  
Vol 253 (2) ◽  
pp. G171-G178
Author(s):  
M. Hatch

Short-chain fatty acid (SCFA) metabolism and transport were examined in vitro across isolated rabbit cecal epithelia whose primary function is absorption of these solutes. This study shows that although there was some low-level metabolism of SCFAs to ketone bodies by the isolated cecum, a significantly higher oxygen consumption was sustained for a longer time period by tissues incubated in glucose-containing salines. The cecum supported a significant net secretory flux of acetate (J net Ac- = -1.13 +/- 0.13 mu eq X cm-2 X h-1) and propionate (J net Pr- = -0.61 +/- 0.14 mu eq X cm-2 X h-1). This study also shows that glucose significantly enhanced short-circuit current (Isc), tissue conductance (Gt), and sodium transport across this tissue. Neither Ac- nor Pr- enhanced net sodium flux (J net Ac-) but Pr- significantly reduced net chloride flux (J net Cl-), whereas Ac- had no effect. The increase in Isc and Gt observed in the presence of SCFAs was attributable to the presence of SCFA in the serosal bathing solution alone. To explain the latter finding and the unexpected finding of SCFA secretion, the existence of an electrogenic anion (HCO3-) secretory pathway is postulated. It is suggested that this system can accommodate SCFAs in vitro and that it is a Na+-dependent system located on the basolateral membrane of the cecal cell.


Gut ◽  
1978 ◽  
Vol 19 (9) ◽  
pp. 819-822 ◽  
Author(s):  
N I McNeil ◽  
J H Cummings ◽  
W P James

1991 ◽  
Vol 260 (5) ◽  
pp. G776-G782 ◽  
Author(s):  
J. M. Harig ◽  
K. H. Soergel ◽  
J. A. Barry ◽  
K. Ramaswamy

Human ileal brush-border membrane vesicles were employed to study the mechanisms of short-chain fatty acid (propionate) absorption especially to determine the effects of intravesicular HCO3- and the component of nonionic diffusion. Preloading the vesicles with HCO3- resulted in up to 20-fold "overshoots" of transport, and this effect was not seen with other intravesicular anions. This transport process was very fast (peak uptake 6 s) and was not due to intravesicular buffering by HCO3-. Radiolabeled propionate transport demonstrated transstimulation when the vesicles were preloaded with unlabeled propionate. An inward H+ gradient led to stimulation of propionate transport much smaller than in the presence of trans-HCO3-, whereas an inward Na+ gradient had no effect. Propionate transport was attenuated by the anion exchange inhibitors SITS and DIDS. Under HCO3- gradient conditions, propionate transport exhibited saturation kinetics with an apparent Km of 21 +/- 3 mM and a Vmax of 50 +/- 3 nmol.mg protein-1.3 s-1. Propionate transport was inhibited up to 40% by 2-5 carbon short-chain fatty acids (10 mM) but not by other organic anions. Short-chain fatty acid transport in the human ileum is Na+ independent and occurs mostly via a specific anion exchange mechanism with HCO3-. Our results also demonstrate a small component of nonionic diffusion of the protonated fatty acid (or anion exchange for OH-).


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