Immune function after relief of obstructive jaundice by internal and external drainage

Background. Obstructive jaundice is associated with a high postoperative complications and mortality. The role of preoperative relief of obstructive jaundice is controversial. Aims. To study the changes of immune function of peripheral leukocytes and liver Kupffer cells in rats with obstructive jaundice and to compare the effects of internal and external drainage on the immune function. Materials and methods. In chapter 7, we developed a simple anaesthetic system for the safe use of inhalational agents in small animals. This scavenger system significantly removed the waste anaesthic gas when it was operational. In chapter 8, we developed a simple and reproducible rat model that allows the studies of the reversal of obstructive jaundice by internal and external drainage with a low mortality rate. The liver function and histological changes showed that the liver was significantly impaired in rats with obstructive jaundice. Internal drainage completely reversed the changes, but external drainage only partially reversed them. We also showed that isoflurane is superior to halothane in reducing surgical mortaltity after drainage. In chapter 9, we showed a novel technique for isolation and purification of Kupffer cells by flow cytometry. Kupffer cells wore sorted with flow cytometry based on the properties of cell size (FSC) and auto-fluorescence (FL1). The identity of the isolated Kupffer cells was performed with electron microscopy, immunocytochemistry, peroxidase staining and phagocytosis assay. The purity and survival rate of sorted Kupffer cells was up to 90% and 95% respectively. In chapter 10, we optimized the experimental conditions necessary to determine the intracellular H2O 2 production and the phagocytic function of rat leukocytes by flow cytometry using dihydrorhodamine-123 and fluorescent microspheres respectively. Results. In chapter 11, we showed that the phagocytic function of neutrophils and monocytes was significantly depressed in rats using halothane anaesthesia compared with that using isoflurane. In chapter 12, Four groups of rats were studied: sham operation, obstructive jaundice, internal drainage and external drainage. After bile duct ligation, the phagocytic function of neutrophils and monocytes was significantly depressed. The suppressed phagocytic function was significantly improved by internal drainage, but not by external drainage. H2O2 production by monocytes and lymphocytes was significantly increased in jaundiced rats compared with the sham operation rats. Internal drainage completely reversed the increased H2O 2 production, but external drainage partially suppressed it. In chapter 13, We showed that after bile duct litigation, Kupffer cells produced significantly higher extracellular superoxide and nitric oxide anions with LPS as a stimulator. Both drainage methods could reverse the elevated superoxide production. However, the elevated nitric oxide production was only significantly decreased by internal drainage. In chapter 14, we showed that after bile duct litigation, the phagocytic function of Kupffer cells was markedly suppressed and the intracellular H 2O2 production was significantly increased compared with sham operation. Following drainage procedures, the changes were reversed by internal drainage, but not by external drainage. Conclusions. The immune function is impaired in rats with obstructive jaundice. Internal drainage completely reverses the damaged immune function, while external drainage only partially reverses it.