Liver injury by endotoxin given during regeneration following a 70% hepatectomy was examined in Wistar rats. The intravenous administration of endotoxin caused an elevation of the serum GPT level, and severe damage of the remnant liver showing centrilobular necrosis with microthrombi. The highest mortality was induced by the administration of endotoxin to rats 24 h after hepatectomy. Kupffer cells in the regenerative phase of the liver showed an augmented in vitro production of both tumor necrosis factor (TNF) and interleukin-1 (IL-1). The simultaneous administration of heparin and prostagladin E1 (PGE1), which is known to suppress the production of TNF and IL-1, reduced the magnitude of liver injury and the mortality of these rats. The absence of any direct cytotoxic effect of TNF and IL-1 against liver cells suggested that the cytokines, produced by Kupffer cells, play an important but indirect role in the remnant liver injury induced by endotoxin after hepatectomy.

To investigate the causes of hepatic dysfunction after extensive resection of the liver together with pancreatectomy, rats were subjected to sham operation, to 68% hepatectomy alone, to 90% pancreatectomy alone, or to 68% hepatectomy combined with 90% pancreatectomy (hepatopancreatectomy). Solutions of 5% or 20% glucose were infused post-operatively for 48 h at a constant rate (250 ml/kg body weight/day) under fasting conditions. To improve the survival rates of pancreatectomized and hepatopancreatectomized rats given 20% glucose, it was necessary to use insulin. In hepatopancreatectomized rats, infusion of 20% glucose with insulin (1 U/5 g glucose) induced prominent hepatocyte vacuolar degeneration and mitochondrial swelling, associated with reduced hepatic protein content. The severity of histological changes was proportional to the insulin dose and the activity of hepatic glucokinase, a key glycolytic enzyme. These histological changes were observed in pancreatectomized rats albeit in a milder form, but not in sham-operated or hepatectomized rats given 20% glucose nor in any rats given 5% glucose. Our results suggest that hepatopancreatectomy followed post-operatively by a high glucose load and exogenously administered insulin enhances the development of hepatocyte swelling.

We developed a system to measure nitric oxide (NO) concentration during cardiopulmonary bypass in anaesthetized pigs (n = 6). A T-shaped connector, attached to an NO sensor, was mounted in the extracorporeal circuit at two measuring sites: proximal to the membrane oxygenator (venous side) and distal to the arterial line filter (arterial side). After performing a preliminary validation study, we measured plasma NO concentration before and during total cardiopulmonary bypass circulation (non-pulsatile flow 1.5 l/min) and without pulmonary ventilation. After establishing bypass, PaO 2 was 318 -393 mmHg; when PaO 2 was decreased to 80 -100 mmHg, plasma NO concentration in the arterial circuit fell by 39.2 ± 15.6 nM. There was no observable change in plasma NO concentration at the venous circuit. This new system could be useful in monitoring NO concentration during cardiac surgery with cardiopulmonary bypass, and for understanding the possible pathophysiological roles of hyper-nitric oxaemia in cardiopulmonary bypass-related cardiovascular complications.

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