[Effects of antihistamine treatment on immune function in rats with experimental hepatitis].

OBJECTIVE: To investigate the effects of antihistamine treatment on immune function in rats with experimental hepatitis. METHODS: Thirty Wistar rats were randomly allocated into three groups:experimental hepatitis group (EH group), antihistamine treatment group (AH group) and normal control group (NC group). Rats in the EH group received the subcutaneous injection of 40% carbon tetrachloride oil solution and were fed on diet with low-protein, low-choline, high-fat and high-alcohol,while rats in the AH group received antihistamine treatment(ketotifen + vitamin C) additionally.They were sacrificed after 4 weeks, and the levels of serum alanine aminotransferase(ALT), total bilirubin (TBil), histamine(HA), IFNgamma, IL-12, IL-4 and IL-10 were determined. The levels of IL-12 mRNA and IFN-gamma mRNA in liver tissue were determined via real-time reverse transcriptional polymerase chain reaction(RT-PCR). RESULTS: (1) Compared to the NC group, in the EH group, the levels of ALT, TBil, and circulating and intrahepatic HA were significantly increased(P less than 0.05); intrahepatic HA were significantly decreased(P less than 0.05) after antihistamine treatment. (2) Compared to the NC group, in the EH group, the levels of IL-4, IL-10 were significantly increased((0.504+/-0.202)ng/ml and (29.025+/-1.478) pg/ml vs (0.811+/-0.244)ng/ml and (33.72+/-4.293)pg/ml respectively, P less than 0.05), and the levels of IL-12 were decreased ((6.515+/-2.893)pg/ml vs (3.519+/-1.113)pg/ml, P less than 0.05); and after antihistamine treatment the levels of IL-4 and IL-10 were significantly decreased (were (0.423+/-0.168)ng/ml and (30.412+/-3.275)pg/ml, P less than 0.05), the levels of IL-12 were significantly increased (P less than 0.05), but the level of IFNgamma had no significance (P more than 0.05). The levels of intrahepatic IL-12 mRNA and IFNgamma mRNA had similar results. CONCLUSION: Antihistamine treatment may improve liver function and correct Th1/Th2 unbalance.

[Changes in mast cells and hepatic expression of c-kit and stem cell factor in the rat model of chronic hepatitis].

OBJECTIVE: To study the potential role of mast cells and the related molecular mechanism in chronic hepatitis (CH) using a rat model system. METHODS: Thirty Wistar rats (15 males, 15 females; weight range: 230-290 g) were randomly divided into the normal contrast (NC) group and experimental CH group. The CH group received subcutaneous injection of CCl4 and a diet high in cholesterol and alcohol content and low in protein and choline content. Throughout the 4-week modeling period, aseptic blood samples were taken to test plasma tryptase (TS) and hyaluronic acid (HA) levels. The rats were euthanized to assess the changes in liver mast cells by histology and morphology analyses and the changes in liver expression of c-kit and stem cell factor (SCF) proteins by immunohistochemistry and mRNAs by RT-PCR. RESULTS: Compared to the NC group, the CH group had higher plasma and liver concentration of HA (78.09 +/- 38.55 vs. 145.14 +/- 52.54 ng/ml, 51.58 +/- 20.45 vs. 106.59 +/- 43.15 ng/100 mg; t = 2.457 and 2.825 respectively, both P less than 0.05) and TS (0.416 +/- 0.143 vs 0.753 +/- 0.210 mg/ml; t = 4.165, P less than 0.05). The CH group also showed fatty degeneration and fibrosis with many degranulating and degranulated mast cells filled with purple granula located around the liver blood vessels and in fiber-intervals. The CH livers also showed a significantly higher number of mast cells (2.167 +/- 0.924 vs. NC: 10.92 +/- 1.575; t = 7.633, P less than 0.05) and stronger intensity of c-kit staining (2.783 +/- 0.577 vs. 12.86 +/- 3.126; t = 9.511, P less than 0.05) and SCF staining (3.383 +/- 1.583 vs. 15.58 +/- 6.431; t = 9.625, P less than 0.05). The expressions of c-kit and SCF were positively correlated with HA level (r = 0.478 and 0.556 respectively, both P less than 0.05). The c-kit and SCF mRNA expression levels were also significantly higher in the CH liver tissues. CONCLUSION: Mast cell degranulation and histamine release is significantly increased under conditions of chronic hepatitis, and the related mechanism may involve up-regulation of the membrane receptor c-kit and its ligand SCF.

[Effects of lipopolysaccharide on the maturation and secretion of human peripheral dendritic cells].

OBJECTIVE: To study the effects of Lipopolysaccharide (LPS) on the maturation and secretion of human peripheral dendritic cells (DCs). METHODS: DCs from healthy human peripheral monocytes (PBMCs) were induced in vitro with rhGM-CSF, rhIL-4, Flt3-L and TNFalpha. The subjects were divided into 3 groups: the long-term group stimulated with LPS 1 microg/ml at day 1, 4, 7, 9 post culture; the short-term group stimulated with LPS 1 microg/ml at day 7 and 8 post culture, and the DCs without LPS stimulation was control group. After 10 days of culture, the morphologic features of DCs were observed by light and electron microscopes, the phenotypic patterns were characterized by flow cytometry, the proliferation of T cell were evaluated with mixed leukocytes reaction (MLR) and the levels of IL-12 and IFNgamma produced by DCs were analyzed with ELISA. RESULTS: Compared with the short-term group, the expressions of HLA-DR (65.81%+/-10.96%), CD86 (48.81%+/-18.13%), CD80 (13.56%+/-5.48%), CD83 (11.52%+/-5.09%), the secretions of IFNgamma(15.60+/-5.83 pg/ml) and IL-12 (51.77+/-11.02 pg/ml) by the DCs in long-term group were decreased obviously (P is less than 0.05) and the proliferation of homogenic lymphocyte cells (1.548+/-0.365) stimulated by DCs was also impaired (P < 0.05). CONCLUSION: Long-term LPS stimulation can suppress the maturation and secretion of DCs, which might be the reason of poor immunity in the patients with intestinal endotoxemia.