Animals ; Carbon Tetrachloride Poisoning ; Diabetes Mellitus, Experimental ; complications ; Liver Cirrhosis, Experimental ; chemically induced ; complications ; pathology ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVESTo study the role of hepatic sinusoid capillarization during the formation of portal hypertension in fibrotic rats induced by dimethylnitrosamine (DMN).

METHODSHepatic fibrotic rats were induced by administration of DMN intraperitoneally three times a week for 4 weeks. The rats were harvested on day 2 and weeks 1, 2, 3, 4, 5, 6, 8, 12 and 24. The formation of liver fibrosis and hepatic sinusoid capillarization were observed by morphologic methods. Pressure of portal vein (Ppv) was directed measured with intubation tube method by mesentry anterior vein.

RESULTSThe Ppv was getting higher and higher with the administration of DMN. After four weeks, the Ppv was higher than that of control [(1.10+/-0.18)kPa vs (0.52+/-0.04)kPa, t=6.41, P<0.01]. The dynamic change of hepatic sinusoid capillarization was in accordance with that of Ppv, which normalized gradually after the DMN was stopped. Significant positive correlation existed between the dynamic change of Ppv and the expression of vWF, laminin and alpha-SMA in sinus (r=0.833, P<0.01; r=0.953, P<0.01; r=0.919, P<0.01).

CONCLUSIONHepatic sinusoid capillarization is the vital cause for portal hypertension in fibrotic rats induced by DMN.

Animals ; Capillaries ; pathology ; Dimethylnitrosamine ; Hypertension, Portal ; chemically induced ; etiology ; pathology ; Liver ; blood supply ; pathology ; Liver Cirrhosis, Experimental ; chemically induced ; complications ; pathology ; Male ; Rats ; Rats, Wistar

BACKGROUNDIt is generally accepted that spleen plays a complex role in the tumor immunity, which would change in the different periods of cancer. In this study, we investigated the changes in the function of splenic macrophage (Mphi) in different stages of liver cancer induced by diethylnitrosamine (DEN) in rats. The aim was to support the characteristics of "two-way" and "phase" of spleen in tumor immunity.

METHODSThe model of pulmonary metastasis of liver cancer was established in forty male SD rats by DEN. In the 8th, 13th and 16th week, 10 rats were randomly chosen and sacrificed, and divided into cirrhosis, liver cancer and pulmonary metastasis groups depending on the pathological result, respectively. The other 10 rats were taken as control group. The Mphi was isolated by anchoring cultivation. The changes in ultrastructure, phagocytosis, cytokine secretion, antigen processing and presenting, and viability of splenic Mphi were detected by transmission electron microscopy, Vybrant(TM) Phagocytosis Assay, DQ(TM) Ovalbumin, and rat TNF-alpha ELISpot kits.

RESULTSUnder the electron microscope, the Mphi in the control group had some pseudopodium-like prominences, and mitochondria, ribosome, rough endoplasmic reticulum, lysosome can be found in the cytoplasm, and phagocytized RBC. In the liver cirrhosis and liver cancer group, Mphi had more prominences, meanwhile much more mitochondria, ribosome, rough endoplasmic reticulum, lysosome can be found in the cytoplasm, especially in the liver cancer group. In the pulmonary metastasis group, the Mphi was swelling, with few organelle. As compared to the control group, the function of splenic Mphi increased in cirrhosis and cancer groups, but decreased in metastasis group (phagocytosis rate: (84.7 +/- 1.9)%, (89.5 +/- 3.1)%, and (36.0 +/- 2.6)% vs (75.6 +/- 1.7)%, P < 0.05, P < 0.01; viability: (1.53 +/- 0.15)%, (1. +/- 0.14)%, and (1.12 +/- 0.29)% vs (1.48 +/- 0.17)%, P < 0.05, P < 0.01; TNF-alpha secretion: (741.0 +/- 52.9)%, (1126.2 +/- 174.5)%, and (313.8 +/- 50.8)% vs (626.6 +/- 24.6)%, P < 0.05, P < 0.01; positive cell rate of antigen processing and presenting: (24.03 +/- 1.87)%, (27.95 +/- 2.63)%, and (10.46 +/- 2.16)% vs (16.45 +/- 1.86)%, P < 0.01).

CONCLUSIONSIn the stage of cirrhosis and early cancer, the immune functions of splenic Mphi were reinforced. It may promote the non-specificity tumor immunity. On opposite, in the stage of pulmonary metastasis, the immune functions of splenic Mphi were impaired. It may lead to the decrease of tumor immunity.

Animals ; Cells, Cultured ; Diethylnitrosamine ; toxicity ; Disease Models, Animal ; Liver Cirrhosis ; immunology ; pathology ; Liver Neoplasms, Experimental ; chemically induced ; complications ; immunology ; ultrastructure ; Lung Neoplasms ; immunology ; secondary ; ultrastructure ; Macrophages ; pathology ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; Rats ; Rats, Sprague-Dawley ; Spleen ; pathology ; ultrastructure

BACKGROUND/AIMS: Ischemic preconditioning (IP) decreases severity of liver necrosis and has anti-apoptotic effects in previous studies using liver regeneration in normal rats. This study assessed the effect of IP on liver regeneration after hepatic resection in cirrhotic rats. METHODS: To induce liver cirrhosis, thioacetamide (300 mg/kg) was injected intraperitoneally into Sprague-Dawley rats twice per week for 16 weeks. Animals were divided into four groups: non-clamping (NC), total clamping (TC), IP, and intermittent clamping (IC). Ischemic injury was induced by clamping the left portal pedicle including the portal vein and hepatic artery. Liver enzymes alanine transaminase (ALT) and aspartate aminotransferase (AST) were measured to assess liver damage. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining for apoptosis and proliferating cell nuclear antigen (PCNA) staining for cell replication were also performed. RESULTS: Day-1 ALT and AST were highest in IP, however, levels in NC and IC were comparably low on days 1-7. There was no significant correlation of AST or ALT with experimental groups (P=0.615 and P=0.186). On TUNEL, numbers of apoptotic cells at 100x magnification (cells/field) were 31.8+/-24.2 in NC, 69.0+/-72.3 in TC, 80.2+/-63.1 in IP, and 21.2+/-20.8 in IC (P<0.05). When regeneration capacity was assessed by PCNA staining, PCNA-positive cells (cells/field) at 400x were 3.4+/-6.0 in NC, 16.9+/-69 in TC, 17.0+/-7.8 in IP and 7.4+/-7.6 in IC (P<0.05). CONCLUSIONS: Although regeneration capacity in IP is higher than IC, the liver is vulnerable to ischemic damage in cirrhotic rats. Careful consideration is needed in applying IP in the clinical setting.
Alanine Transaminase/blood ; Animals ; Apoptosis ; Aspartate Aminotransferases/blood ; Constriction ; Hepatectomy/methods ; Hepatic Artery ; *Ischemic Preconditioning ; Liver/blood supply ; Liver Cirrhosis, Experimental/chemically induced/complications/*pathology ; *Liver Regeneration ; Proliferating Cell Nuclear Antigen/metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury/complications/enzymology/pathology ; Thioacetamide/toxicity