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Mesenteric Venous Stenosis Reduces Hyperammonemia in the Portacaval Shunted Rat

  • Kaj Johansen
  • Catherine Girod
  • Samuel S. Lee
  • Didier Lebrec
Chapter
Part of the Experimental Biology and Medicine book series (EBAM, volume 22)

Abstract

Hyperammonemia is a constant finding following portacaval anastomosis (PCA), and has been incriminated in the genesis of post-shunt encephalopathy (PSE) in the human. We developed a model for mesenteric venous hypertension in the rat by modification of a commonly-used technique for studying extrahepatic portal hypertension. We then examined serum ammonia levels in rats undergoing sham operation, mesenteric vein stenosis (MVS) alone, PCA alone, and MVS plus PCA.

MVS animals had significant (p < 0.05) elevation in mesenteric venous pressures two to three weeks after operation. Serum ammonia levels were normal in rats undergoing sham operation and MVS, and were significantly elevated (p < 0.001) in rats with PCA. However, combination of MVS and PCA resulted in a significant (p < 0.01) reduction in serum ammonia levels.

These data suggest that ammonia absorption from the intestine is a function of splanchnic venous pressure. This finding may be relevant to the management of the neuropsychiatric deterioration seen following PCA in the human.

Keywords

Hepatic Encephalopathy Portacaval Shunt Portal Vein Stenosis Serum Ammonia Level Portacaval Anastomosis 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. 1.
    Walker CO, Schenker S. Pathogenesis of hepatic encephalopathy with special reference to the role of ammonia. Am J Clin Nutr 1977; 23:619–632.Google Scholar
  2. 2.
    Zieve L. The mechanism of hepatic coma. Hepatology 1981; 1:360–368.PubMedCrossRefGoogle Scholar
  3. 3.
    Harrison ID, Smith AH, Shields R. Ammonia absorption from the canine colon after portacaval shunt. Brit J Surg 1977; 64:851–856.PubMedCrossRefGoogle Scholar
  4. 4.
    Enquist IF, Golding MR, Iello RG, et al. The effect of portal hypertension on intestinal absorption. Surg Gynecol Obstet 1965; 120:87–91.PubMedGoogle Scholar
  5. 5.
    Price JB, McCullough W, Peterson L, Britton RC, Voorhees AB. Effects of portalsystemic shunting on intestinal absorption in the dog and man. Surg Gynecol Obstet 1967; 125:305–310.Google Scholar
  6. 6.
    Windsor CW, Goodhead B, Orloff MJ. Effects of portacaval shunts in experimental liver disease on intestinal absorption of ammonia. Surg Forum 1968; 19:333–335.PubMedGoogle Scholar
  7. 7.
    Orloff MJ, Wall MH, Hickman EB, Neesley T. Influence of stomal size of portacaval shunts on peripheral blood ammonia levels. Ann Surg 1963; 158:172–175.PubMedCrossRefGoogle Scholar
  8. 8.
    Castell DO, Moore EW. Ammonia absorption from the human colon: the role of non-ionic diffusion. Gastroenterology 1971; 60:33–42.PubMedGoogle Scholar
  9. 9.
    Sein MM, Hardy-Smith A, Shields R. Effect of portacaval shunt on colon transfer of ammonia in cirrhosis of the liver. Gut 1974; 15:837–840.PubMedGoogle Scholar
  10. 10.
    Lebrec D, Blanchet L. Effect of two models of portal hypertension on splanchnic organ blood flow in the rat. Clin Sci 1985; 68:23–28.PubMedGoogle Scholar
  11. 11.
    Halvorsen JF, Myking AO. Prehepatic portal hypertension in the rat — immediate and long-term effects on portal vein and aortic pressure of a graded portal vein stenosis, followed by occlusion of the portal vein and splenorenal collaterals. Eur Surg Res 1979; 11:89–98.PubMedCrossRefGoogle Scholar
  12. 12.
    Lee S, Fisher B. Portacaval shunt in the rat. Surgery 1961; 14:668–672.Google Scholar
  13. 13.
    Castaing D, Bismuth H. L’Anastomose porto-cave chez le rat: 20 ans de modele experimental. Gastroenterol Clin Biol 1984; 8:469–479.PubMedGoogle Scholar
  14. 14.
    Hess F, Jerusalem C, Willemen A. Altered portal pressure secondary to portacaval and portasystemic shunts in the rat: the effect on liver function and intestinal integrity. Eur J Surg Res 1982; 14:286–297.CrossRefGoogle Scholar
  15. 15.
    Starzl TE, Porter KA, Francavilla JA. A hundred years of the hepatotrophic controversy. Hepatotrophic factors. Ciba Symposium, Amsterdam, Elsevier (1978), 111–138.Google Scholar
  16. 16.
    Warren WD. Control of variceal bleeding; reassessment of rationale. Am J Surg 1983; 145:8–16.PubMedCrossRefGoogle Scholar
  17. 17.
    Rikkers LF. Portal hemodynamics, intestinal absorption, and post-shunt encephalopathy. Surgery 1983; 94:126–133.PubMedGoogle Scholar
  18. 18.
    Sarfeh IJ, Rypins EB, Fardi M, Conroy RM, Mason GR, Lyons KP. Clinical implications of portal hemodynamics after small-diameter portacaval H-graft. Surgery 1984; 96:223–229.PubMedGoogle Scholar
  19. 19.
    Johansen K. Partial portal decompression: initial clinical experience with small-stoma portacaval shunt. Am J Surg, in press.Google Scholar

Copyright information

© The Humana Press Inc. 1989

Authors and Affiliations

  • Kaj Johansen
    • 1
  • Catherine Girod
    • 1
  • Samuel S. Lee
    • 1
  • Didier Lebrec
    • 1
  1. 1.Unité de Recherches de Physiopathologie Hepatique (INSERM U-24)Hopital BeaujonClichyFrance

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