Inhibition of short-chain fatty acid absorption and Na+ absorption during acute colitis in the rabbit.
OBJECTIVE
Short-chain fatty acids (SCFAs) provide energy for colonocytes and stimulate colonic fluid and electrolyte absorption. The impact of acute colitis on SCFA-stimulated Na+ absorption and SCFA absorption was examined.


METHODS
Proximal colon from rabbits infected with Yersinia entercolitica, a pair-fed group, and controls was mounted in Ussing chambers, and Na+ transport, short-circuit current, and tissue conductance were examined during a basal period and after stimulation with the SCFAs, butyrate, or propionate. Propionate transport and luminal SCFA concentration were evaluated.


RESULTS
Butyrate and propionate stimulated electroneutral Na+ absorption above basal levels in the control and pair-fed groups, as evidenced by significant increases in mucosal-to-serosal and net Na+ fluxes with no change in serosal-to-mucosal flux, short-circuit current, or conductance. Butyrate-stimulated Na+ absorption and propionate absorption were blocked by amiloride, an inhibitor of Na(+)-H+ exchange. In the infected group, both butyrate and propionate failed to stimulate colonic Na+ absorption above basal levels. Propionate absorption was inhibited, and epinephrine failed to stimulate Na+ or propionate absorption. Luminal SCFA concentrations were increased in acute colitis.


CONCLUSIONS
Inhibition of SCFA-stimulated Na(+)-H+ exchange and SCFA absorption contribute to the diarrheal fluid loses observed in acute colitis and may reduce colonocyte energy supply.
Butzner
J D
JD
Gastrointestinal Research Group, University of Calgary, Alberta, Canada.
Meddings
J B
JB
Dalal
V
V
D000208:Acute Disease; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D002087:Butyrates / Q000494:pharmacology; D003092:Colitis / Q000378:metabolism* / Q000382:microbiology / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000494:pharmacology; D005232:Fatty Acids, Volatile / Q000493:pharmacokinetics* / Q000494:pharmacology / Q000502:physiology; D007408:Intestinal Absorption / Q000187:drug effects / Q000502:physiology*; D011422:Propionates / Q000494:pharmacology; D011817:Rabbits; D012964:Sodium / Q000493:pharmacokinetics*; D015009:Yersinia Infections / Q000378:metabolism; D015008:Yersinia enterocolitica
D002087:Butyrates; D005232:Fatty Acids, Volatile; D011422:Propionates; D000584:Amiloride; D012964:Sodium; D004837:Epinephrine