Acute Hepatic Encephalopathy in the Rat: The Effect of Cross-Circulation

Abstract

1. The effect of cross-circulation on hepatic encephalopathy (evaluated by electroencephalography; EEG) induced by hepatectomy in the rat was examined.2. Systemiosystemic cross-circulation induced improvement of the altered EEG in only two out of seven liverless rats when the exchange-flow rate was 6.4 ml min-' kg body wt.-', and in all seven liverless rats when the exchange-flow rate was 14.0 ml min-kg body wt.-; the difference is statistically significant (P = 0.01 1). Systemioportal cross-circulation (systemic blood from the liverless rat beinginfused into the portal vein of the normal rat) induced improvement of the altered EEG in all seven liverless rats although the exchange-flow rate was only 6.4 ml min-' kg body wt.-' 4. It is concluded (a) that a certain level of exchange-flow rate is required for cross-circulation to be efficient, and (b) that, for the same exchange-flow rate, systemio portal cross-circulation is more efficient than systemiosystemic cross-circulation.

Hepatic Encephalopathy: From the Pathogenesis to the New Treatments

“…Under this light, portal-systemic shunting plays a critical role, as the main impact of this circulatory disturbance is on the concentration of gut-derived substances that are highly cleared by the liver. Studies of cross-perfusion in animals with experimental HE and liver support systems in humans have shown that clearance of toxic substances present in the blood is more important to improve mental function than the synthetic capacity of the support system [ 5 ]. In patients with liver disease, these toxic substances reach the systemic circulation as a result of portal-systemic shunting or reduced hepatic clearance and produce deleterious effects on brain function.…”

Hepatic Encephalopathy

“…However, experimental and clinical evidence does not support this concept. Cross-perfusion experiments in a rat model of hepatic liver failure showed that depuration of its blood through a normal liver is far more critical for an adequate mental state than the provision of liver-derived blood from a normal animal [21]. For many years, the controversy has centred around the nature of gut-derived toxins.…”

Long‐Term Cultures of Adult Mammalian Hepatocytes in Hollow Fibers as the Cellular Component of Extracorporeal (Hybrid) Liver Assist Devices

“…Furthermore, in lieu of animal experimentation some laboratories have opted to measure functional hepatocyte activities in hollow fiber devices perfused in vitro, which play IZO role in HE, i.e., the production of albumin. In this context, it should be emphasized that although the pathogenesis of HE is unknown, carefully designed crosscirculation experiments do not support the possibility of a diminished hepatic synthesis of a substance necessary for brain function in FHF (14). Rather, there is a general agreement that a diminished hepatic catabolism of certain (gut-derived) metabolites or endotoxins is taking place (8).…”