Congenital portacaval shunt in rats: Liver adaptation to lack of portal vein—a light and electron microscopic study
✍ Scribed by Paulette Bioulac-Sage; Jean Saric; Lilianne Boussarie; Charles Balabaud
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- English
- Weight
- 926 KB
- Volume
- 5
- Category
- Article
- ISSN
- 0270-9139
No coin nor oath required. For personal study only.
✦ Synopsis
In five rats with congenital portacaval shunt, liver atrophy, hyperplastic foci in the periportal zone, atrophic hepatocytes in the centrolobular zone, well-preserved hepatocyte ultrastructure with abundant rough endoplasmic reticulum, packed mitochondria and numerous peroxisomes were h r v e d as in surgical portacaval shunt. However, portal triads were abnormal' in contrast to surgical shunt. In large portal triads, hepatic arteries were prominent, bile ducts numerous and portal veins were lacking. Instead, small or large capillariee were seen in the portal tracts usually at the periphery. These capillaries appeared to be in continuity with nearby sinueoids preeenting the ultrastructural characteristics of capillaries. These obeervations suggest that absence of the portal vein is compensated by formation of neocapillariee. It is assumed that these capillariee originate from periportal sinueoids and are necessary to distribute blood to all sinusoids and form a reservoir to lower arterial pressure.
Deprivation of portal blood in rats leads to liver atrophy. Weeks after surgical portacaval shunt (S-PCS), zonal heterogeneity appears with hyperplastic areas in periportal zone 1 and atrophic areas in centrolobular zone 3 (1, 2). The absolute increase in hepatic arterial blood flow maintains normal hepatic blood flow per gram of liver tissue (3). In light of this, it is reasonable to assume that distribution of hepatic arterial blood flow remains normal (4) with a small portion flowing directly into sinusoids and a large portion going directly or indirectly into terminal portal veins and then into sinusoids.
Congenital portacaval shunt (C-PCS) is a rare event but is interesting because it represents a pure model without interferences such as necrosis which occurs im- mediately after the surgical shunt ( 5 ) . In addition, extraand intrahepatic portal veins are lacking (6), raising important questions about the perfusion of sinusoids from the hepatic artery.
We observed five such cases. The aim of this study is to report hepatic light and electron microscopic findings with particular emphasis on portal tracts (PT) and neighboring sinusoids.