Acute portal hypertension reflecting shear stress as a trigger of liver regeneration following partial hepatectomy
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The concept of injury in liver regeneration after partial hepatectomy (PHx), and the reason hepatocytes that have not been directly injured regenerate, remain unclear. It is known that shear stress resulting from blood flow plays an important role in the mechanism of remodeling blood vessels, and portal pressure reflects shear stress. This study was conducted to determine whether acute portal hypertension (APH) can become a trigger of liver regeneration as shear stress following PHx in a rat model. Portal pressures became elevated immediately after 70% and 90% PHx, peaking on postoperative day (POD) 3, and thereafter decreasing in proportion to the diminution of liver regeneration. The portal pressures after 90% PHx were significantly higher than those after 70% PHx even on POD 7, while those of the portocaval (PC) shunt groups decreased following PC shunting both with and without 70% PHx. The liver/body weight (LW/BW) ratio also decreased in the PC shunt both with and even without 70% PHx. The gradient expressions of class I antigen on sinusoidal endothelial cells (SEC) were found only in the periportal area, which has the highest portal pressure in the healthy rat liver. However, after hepatectomy these expressions were detected from the periportal area to the central venous area. These results suggest that APH as shear stress following PHx may not only become a trigger of hepatocyte regeneration, but also of SEC regeneration, and that surplus APH induces liver dysfunction.
Key Wordsliver regeneration partial hepatectomy portal pressure shear stress rats
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- 1.Leffert HL, Koch KS (1980) Ionic events at the membrane initiate rat liver regeneration. Ann NY Acad Sci 888:201–215Google Scholar
- 2.Thoma R (1911) Über die Histomechanik des gefa Systems und die Pathogenese der Angiosklerose. Path Anat Physiol 204:1–74Google Scholar
- 5.Ohno M, Lopez F, Gibbons GH, Cooke JP, Dzau VJ (1992) Shear stress-induced TGF-β 1 is mediated via a K+ channel (abstract). Circulation 86:I-87Google Scholar
- 7.Higgins GM, Anderson RM (1931) Experimental pathology of the liver of the white rat following partial surgical removal. Arch Pathol 12:186–202Google Scholar
- 9.Bucher NLR, McGowan JA, patel U (1987) Hormonal regulation of liver growth. In: Dirksen ER, Prescott DM, Fox CF (eds) Cell reproduction. ICN/UCLA Symposium on Molecular Biology. Academic, New York, pp 661–670Google Scholar
- 17.Oda M, Nakamura M, Watanabe N, Ohya Y, Sekuzuka E, Tsukada N, Yonei Y (1983) Some dynamic aspects of the hepatic microcirculation-demonstration of sinusoidal endothelial fenestrae as a possible regulatory factor. In: Tsuchiya M, Wayland H, Oda M, Okazaki I (eds) Intravital observation of organ microcirculation. Excerpta Medica, Amsterdam, pp 105–138Google Scholar
- 18.Nakata K (1961) Direct measurement of blood pressures in minute vessels of the liver. Am J Physiol 199:1181–1188Google Scholar
- 21.Sonsoles H, Beatrice D, Ana MG, Maria JM D-G, Lisardo B (1995) Nitric oxide is released in regenerating liver after partial hepatectomy. Hepatology 21:776–786Google Scholar
- 25.Sato Y, Inoue S, Nagao T, Yoshida K, Akiyama N, Muto T (1991) Cyclosporine suppresses class II antigen expression in regenerating liver of rats after partial hepatectomy. Nippon Shokaki Geka Gakkai Zasshi (Jpn J Gastroenterol Surg) 24:172Google Scholar
- 26.Sato Y, Tsukada K, Koyama S, Hatakeyama K. Acute portal hypertension and activation of sinusoidal endothelial cells: Hypothesis of mechanism of hepatic necrosis following hepatectomy. Res Surg (in press)Google Scholar
- 33.Fausto N (1990) Hepatic regeneration. In: Zakim D, Boyer TD (eds) Hepatology: a textbook of liver disease. Saunders, Philadelphia, pp 49–61Google Scholar