Uremia increases gastric mucosal permeability and acid back-diffusion injury in the rat.
The possibility that chronic uremia renders the gastric mucosa more susceptible to acid injury was investigated. A rat model of chronic renal failure was induced by subtotal nephrectomy. [H+] back-diffusion across the mucosa, following intragastric perfusion of 0.15N HCl or 15% ethanol in 0.15N HCl, was significantly greater in uremic than in sham-operated rats. Gastric mucous gel thickness and transmural potential difference were significantly lower in rats with renal insufficiency. Furthermore, a significantly greater acidification rate of the surface epithelial cells was found in uremic rats than in sham-operated rats during superfusion with pH 1.7 buffer. Intragastric administration of acidified ethanol or aspirin solutions markedly increased gastric mucosal blood flow (68% and 89% respectively) in the sham-operated group producing mild injury, in contrast to uremic rats, where a lesser increase in mucosal blood flow (7% and 14% respectively) was associated with more pronounced mucosal injury. It was concluded that enhanced susceptibility to acid injury in uremia is due to a reduction of function of pre-epithelial, epithelial, and postepithelial elements of the gastric mucosal barrier.
Quintero
E
E
Medical Service, Veteran's Affairs Medical Center West Los Angeles, California.
Kaunitz
J
J
Nishizaki
Y
Y
De Giorgio
R
R
Sternini
C
C
Guth
P H
PH
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis / Q000276:immunology; D002211:Capsaicin / Q000494:pharmacology; D004058:Diffusion; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D005753:Gastric Mucosa / Q000098:blood supply / Q000294:innervation / Q000378:metabolism*; D008297:Male; D010539:Permeability; D051381:Rats; D017207:Rats, Sprague-Dawley; D014511:Uremia / Q000378:metabolism*
D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin