Effect of Soothing Gan (Liver) and Invigorating Pi (Spleen) Recipes on TLR4-p38 MAPK Pathway in Kupffer Cells of Non-alcoholic Steatohepatitis Rats.

OBJECTIVE: To investigate the mechanism of inflflammatory-mediated toll-like receptor 4 (TLR4)-p38 mitogen-activated protein kinase (p38 MAPK) pathway in Kupffer cells (KCs) of non-alcoholic steatohepatitis (NASH) rats and the intervention effect of soothing Gan (Liver) and invigorating Pi (Spleen) recipes on this pathway. METHODS: After 1 week of acclimatization, 120 Sprague-Dawley male rats were randomly divided into 8 groups using a random number table (n=15 per group): normal group, model group, low-dose Chaihu Shugan Powder (, CHSG) group (3.2 g/kg), high-dose CHSG group (9.6 g/kg), low-dose Shenling Baizhu Powder (, SLBZ) group (10 g/kg), high-dose SLBZ (30 g/kg) group, and low- and highdose integrated recipe (L-IR, H-IR) groups. All rats in the model and treatment groups were fed with a high-fat diet (HFD). The treatments were administrated by gastrogavage once daily and lasted for 26 weeks. The liver tissues were detected with hematoxylin-eosin (HE) and oil red O staining. Levels of liver lipids, serum lipids and transaminases were measured. KCs were isolated from the livers of rats to evaluate the mRNA expressions of TLR4 and p38 MAPK by real-time flfluorescence quantitative polymerase chain reaction, and proteins expressions of TLR4, p-p38 MAPK and p38 MAPK by Western blot. Levels of inflammatory cytokines including tumor necrosis factor α (TNF-α), interleukin (IL)-1 and IL-6 in KCs were measured by enzyme-linked immunosorbent assay. RESULTS: After 26 weeks of HFD feeding, HE and oil red O staining showed that the NASH model rats successfully reproduced typical pathogenesis and histopathological features. Compared with the normal group, the model group exhibited significant increases in body weight, liver weight, liver index, serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol, and aspartate aminotransferase as well as TC and TG levels in liver tissues, and significant decrease in serum level of high-density lipoprotein cholesterol (Plt;0.05 or Plt;0.01), while those indices were significantly ameliorated in the H-IR group (Plt;0.05 or Plt;0.01). Higher levels of TNF-α, IL-1 and IL-6 in KCs were observed in the model group compared with the normal group (Plt;0.01). Significant decreases in TNF-α, IL-1 and IL-6 were observed in the H-SLBZ, H-IR and L-IR groups compared with the model group (Plt;0.05 or Plt;0.01). The mRNA expressions of TLR4 and p38 MAPK and protein expressions of TLR4, p38 MAPK and p-p38 MAPK in KCs in the model group were significantly higher than the normal group (Plt;0.01), while those expression levels in the L-IR and H-IR groups were significantly lower than the model group (Plt;0.05 or Plt;0.01). CONCLUSION: Inflflammation in KCs might play an important role in the pathogenesis of NASH in rats. The data demonstrated the importance of TLR4-p38MAPK signaling pathway in KCs for the anti-inflflammatory effect of soothing Gan and invigorating Pi recipes.

Effects of Soothing Liver and Invigorating Spleen Recipes on the IKKß-NF-κB Signaling Pathway in Kupffer Cells of Nonalcoholic Steatohepatitis Rats.

This study investigates the effect of soothing liver and invigorating spleen recipes on steatohepatitis examining the IKKß-NF-κB signaling pathway in KCs of NASH rats. SD male rats were randomly divided into 8 groups, and the NASH model was induced by a high-fat diet (HFD). After 26 weeks, liver tissue was examined in H&E stained sections and liver function was monitored biochemically. KCs were isolated by Seglen's method, with some modifications. The mRNA and protein expression of the IKKß-NF-κB signaling pathway components was examined by quantitative PCR and Western blotting. The results show that the high-fat diet induced NASH in the rats, and the soothing liver recipe and invigorating spleen recipe decreased the levels of TNF-α, IL-1, and IL-6 in KCs, as well as inhibiting the mRNA and protein expression of the IKKß-NF-κB signaling pathway components. In conclusion, the experiment indicated the importance of the IKKß-NF-κB signaling pathway in KCs for the anti-inflammatory effects of the soothing liver and invigorating spleen recipes.

[Effects of soothing liver and invigorating spleen recipes on SREBP-1c, SCD-1 mRNA and proteins expression in hepatocytes of NAFLD rats].

OBJECTIVE: To observe the effects of soothing liver and invigorating spleen recipes on the expression levels of SREBP-1c, SCD-1 mRNA and proteins in hepatocytes of NAFLD rats,and to explore its possible mechanisms of prevention and treatment of NAFLD. METHODS: 75 SD male rats were randomly divided into 5 groups: normal group, model group, oothing liver group (administrated with 9.6 g/kg), invigorating spleen group (administrated with 30 g/kg)and integrated group (administrated with 39.6 g/kg). The rats of NASH model were induced by feeding a high-fat diet. After treatment for 8 weeks,9 rats were randomly taken to detect liver function, TC, TG and pathological changes in liver tissue. The other 6 rats of each group were taken respectively and collagenase (Type IV) was perfused to digest liver tissue with the circulation in vitro to separate hepatocytes. Real-time Q-PCR and Western Blot were used to detect the expression levels of SREBP-1c, SCD-1 mRNA and proteins. RESULTS: Compared with the model group,the different decrease levels of SREBP-1c, SCD-1 genes and proteins were found in all drug therapy groups (P < 0.05 or P < 0.01), as well different degrees that liver lipid and pathological changes became better, especially that of in soothing liver group. Comparison between the all drug therapy groups,the hepatocytes expression levels of SREBP-1c and SCD-1 mRNA in soothing liver group were lower than that of in invigorating spleen group (P < 0.05), but expression levels of the proteins had no statistical significances. CONCLUSION: Soothing liver and invigorating spleen recipes prevent and treat NAFLD,its mechanism may be related to inhibiting the activation of SREBP-1c/SCD-1 signal pathway in hepatocytes to down-regulate TC and TG synthesis and reduce hepatic lipid deposition. SREBP-1c, SCD-1 mRNA and proteins may be the effective targets.

Effects of Chaihu-Shugan-San and Shen-Ling-Bai-Zhu-San on p38 MAPK Pathway in Kupffer Cells of Nonalcoholic Steatohepatitis.

This study aimed to investigate the effects of Chaihu-Shugan-San (CSS), Shen-Ling-Bai-Zhu-San (SLBZS), and integrated recipe of the above two recipes on inflammatory markers and proteins involved in p38 MAPK pathway in Kupffer cells of NASH rats induced by high fat diet (HFD). Rats were administered at low or high dose of CSS, SLBZS, and integrated recipe except normal group and model group for 16 weeks. The levels of hepatic lipid, TNF- α , IL-1, and IL-6 in liver tissues were measured. Kupffer cells were isolated from livers to evaluate expressions of TLR4, p-p38 MAPK, and p38 MAPK by Western blotting. The results showed that the NASH model rats successfully reproduced typical pathogenetic and histopathological features. Levels of hepatic lipid and liver tissues inflammatory factors in high-dose SLBZS group and integrated recipe group were all lower than that of model group decreased observably. Expressions of TLR4, p-p38 MAPK, and p38 MAPK in Kupffer cells were decreased in all treatment groups, but there was no significant difference between treatment groups. The high-dose SLBZS group had the lowest expression levels of TLR4, and the most visible downtrend in the expression levels of p-p38 MAPK and p38 MAPK was found in the high-dose integrated recipe group. The ratio of p-p38 MAPK to total p38 MAPK protein was obviously increased in all treatment groups. Therefore, our study showed that the activation of p38 MAPK pathway in Kupffer cells might be related to the release of inflammatory factors such as TNF- α , IL-1, and IL-6 in NASH rats. High dose of SLBZS and integrated recipe might work as a significant anti-inflammatory effect in Kupffer cells of NASH rats induced by HFD through suppression of p38 MAPK pathway. It indicated that p38 MAPK pathway may be the possible effective target for the recipes.

[Effect of Shugan Jianpi Recipe on LXRα/FAS signaling pathway mediated hepatocyte fatty deposits in NAFLD rats].

OBJECTIVE: To explore the effect of Shugan Jianpi Recipe (SJR) on LXRα/FAS signaling pathway mediated hepatocyte fatty deposits in nonalcoholic fatty liver disease (NAFLD) rats. METHODS: Totally 75 SPF grade male SD rats were randomly divided into 5 groups, i.e., the normal control group, the model group, the Shugan Recipe (SR) treatment groups, the Jianpi Recipe (JR) treatment group, and the SJR group. Except rats in the normal control group, the NAFLD rat model was duplicated using high fat diet (HFD). SR (Chaihu Shugan Powder) was administered to rats in the SR group. JR (Shenlin Baizhu Powder) was administered to rats in the JR group. SJR (Chaihu Shugan Powder plus Shenlin Baizhu Powder) was administered to rats in the SJR group. Changes of liver fat were analyzed using automatic biochemical analyzer. Liver cells were separated by low-speed centrifugation. Their activities and purities were identify using Typan blue and flow cytometry (FCM). Expression levels of LXRα and FAS mRNA in hepatocytes detected by Real-time quantitative PCR. Expression levels of LXRα and FAS protein were detected by Western blot. RESULTS: (1) Pathological results showed in the model group, hepatocytes were swollen with nucleus locating at the cell edge after oil red O staining; unequal sized small vacuoles could be seen inside cytoplasm. Some small vacuoles merged big vacuoles. All these indi- cated a NAFLD rat model was successfully established by high fat diet. Pathological structural changes could be impaired to some degree in all medicated groups, especially in the SR group. (2) Compared with the normal control group, expression levels of LXRα and FAS genes and proteins obviously increased in the model group (P < 0.01). Compared with the model group, their expression levels were obviously down-regulated in the JR group and the SR group (P < 0.01, P < 0.05). CONCLUSIONS: LXRα/FAS signaling pathway was an important signaling pathway for mediating lipid metabolism disorders of NAFLD rats. SJR could make hepatocyte fatty deposits tend to repair by adjusting the LXRα/FAS signaling pathway in NAFLD rats, which might be one of important mechanisms for SJR to prevent and cure NAFLD.

[Effects of soothing liver and invigorating spleen recipes on NF-kappaB signal pathway related genes and proteins in primary hepatocytes of rats with NASH].

OBJECTIVE: To observe the effects of soothing liver and invigorating spleen recipes on NF-kappaB signal pathway related genes and proteins in primary hepatocytes of rats with NASH. METHODS: SD male rats were randomly divided into 8 groups: normal, model, high/low-dose soothing liver group, high/low-dose invigorating spleen group, high/low-dose integrated group. 15 rats in each group. The NASH model rats were induced by feeding high-fat diet (HFD). The treatment lasted for 16 weeks. Then TC, TG in the liver tissue and serum were determined with automatic biochemical analyzer. HE staining and oil red O staining were operated to observe the pathological changes. Another 6 rats of each group were taken respectively and collagenase (Type IV) was perfused to digest liver tissue with the circulation in vitro to separate hepatocytes. The expression levels of IKK(beta), NF-kappaB mRNA, proteins and phosphorylated IKK(beta) protein in hepatocytes of rats from each group were detected by Real-time Q-PCR and Western Blotting, respectively. RESULTS: Compared with normal group, liver histopathology was changed and levels of TC and TG were elevated in model group indicating hepatocytes had lipid accumulation and lipid metabolic disturbance obviously; The levels of serum TC, and hepatic homogenate TC, TG as well as the expression of IKK(beta) NF-kappa-B mRNA, proteins and phosphorylated IKK(beta) protein in hepatocytes were dramatically increased in model group (P < 0.01). Compared with the model group, the levels of IKK(beta), NF-kappaB mRNA expression were decreased most significanly in the invigorating spleen (with high dose) group and the integrated group (with high dose) (P < 0.01 or P < 0.05). The expression levels of the IKK(beta), NF-kappaB proteins and the phosphorylated IKK(beta) protein in hepatocytes were decreased significaniy in the treatment groups (P < 0.01 or P < 0.05), especially for the invigorating spleen (with high dose) group and the integrated (with high dose). CONCLUSION: Soothing liver and invigorating spleen recipes have effect on NASH rats induced by HFD and its mechanism may be related to the suppression of IKK(beta)/NF-kappaB signal pathway related genes and proteins. And the effect probably has a dose response relationship.

[Ecological characteristics of different Pseudosciaena crocea culture models].

A comparative study was conducted on the ecological characteristics of different Pseudosciaena crocea culture models including monoculture P. crocea (F) and polyculture P. crocea with seaweed Gracilaria lichevoides (FG), benthos Perinereis aibuhitensis (FP), and G. lichevoides plus P. aibuhitensis (FGP) in land-based enclosures, with the sediment and water environment condition, culture benefit, and nitrogen (N) and phosphorus (P) reclaim efficiency analyzed. G. lichevoides could effectively remove the N and P in the water body. The water N and P concentrations in FG and FGP were significantly lower than those in F and FP, and the P utilization efficiency reached 33.8% - 34.0% of the total P input. P. aibuhitensis improved sediment environment condition. The sediment N and P concentrations in FP and FGP were lower than those in F and FG, and had significant differences between surface sediment (1-2 cm) and subsurface sediment (2-4 cm). Comparing with those in F, the total N, total P, and inorganic P in FP and FGP reduced by 8.9% -9.2% , 6.1% -6.3% and 8.0% -8.1%, respectively. P. aibuhitensis had a higher efficiency in reclaiming sediment P (7.5% -7.8% of the total P input), being able to effectively mitigate the P accumulation in sediment. Among the test models, FGP had the best material utilization efficiency and optimal resource benefit.

Cigarette smoke extract promotes proliferation of airway smooth muscle cells in asthmatic rats via regulating cyclin D1 expression.

BACKGROUND: Increased proliferation of airway smooth muscle cells (ASMCs) are observed in asthmatic patients and smoking can accelerate proliferation of ASMCs in asthma. To elucidate the molecular mechanisms leading to these changes, we studied in vitro the effect of cigarette smoke extract (CSE) on the proliferation of ASMCs and the expression of cyclin D1, an important regulatory protein implicated in cell cycle. METHODS: ASMCs cultured from 8 asthmatic Brown Norway rats were studied. Cells between passage 3 and 6 were used in the study and were divided into control group, pcDNA3.1 group, pcDNA3.1-antisense cyclin D1 (ascyclin D1) group, CSE group, CSE + pcDNA3.1 group and CSE + pcDNA3.1-ascyclin D1 group based on the conditions for intervention. The proliferation of ASMCs was examined with cell cycle analysis, MTT colorimetric assay and proliferating cell nuclear antigen (PCNA) immunocytochemical staining. The expression of cyclin D1 was detected by reverse transcriptase-PCR (RT-PCR) and Western blotting. RESULTS: (1) The percentage of S + G2M phase, absorbance value at 490 nm wavelength (A(490)) and the expression rate of PCNA protein in CSE group were (31.22 +/- 1.17)%, 0.782 +/- 0.221, (90.2 +/- 7.0)% respectively, which were significantly increased compared with those of control group ((18.36 +/- 1.02)%, 0.521 +/- 0.109, and (54.1 +/- 3.5)%, respectively) (P < 0.01). After the transfection with antisense cyclin D1 plasmid for 30 hours, the percentage of S + G2M phase, A(490) and the expression rate of PCNA protein in ASMCs were much lower than in untreated cells (P < 0.01). (2) The ratios of A(490) of cyclin D1 mRNA in CSE group was 0.288 +/- 0.034, which was significantly increased compared with that of control group (0.158 +/- 0.006) (P < 0.01). After the transfection with antisense cyclin D1 plasmid for 30 hours, the ratios of A(490) of cyclin D1 mRNA in ASMCs was much lower than in untreated cells (P < 0.01). (3) The ratios of A(490) of cyclin D1 protein expression in CSE group was 0.375 +/- 0.008, which was significantly increased compared with that of control group (0.268 +/- 0.004) (P < 0.01). After the transfection with antisense cyclin D1 plasmid for 30 hours, the ratios of A(490) of cyclin D1 protein expression in ASMCs was much lower than in untreated cells (P < 0.01). CONCLUSION: CSE may increase the proliferation of ASMCs in asthmatic rats via regulating cyclin D1 expression.

[Effects of Ginkgo biloba extract on proliferation and apoptosis of T lymphocytes in vitro in rats with asthma].

OBJECTIVE: To explore the partial therapeutic mechanism of Ginkgo Biloba extract (GBE) in treating asthma. METHODS: Fourteen SD rats were randomly divided into two groups, 7 rats were sensitized as the asthmatic model group and the others taken as the healthy control group. T lymphocytes were isolated from peripheral blood mononuclear cells (PBMCs) of the rats, and were cultured in vitro with Ginkgolide B (BN-52021 group) or Ginkgo Biloba extract 761 (EGb761 group) in different concentrations or without any of them (control group). T lymphocytes proliferation in groups were measured by using MTT assay and the effect of BN-52021 on T lymphocytes apoptosis was analyzed by flow cytometry at various times. RESULTS: Compared with the control group, BN-52021 could significantly inhibit the proliferation of T lymphocytes in both healthy and asthmatic rats in vitro (P <0. 05). The effects were enhanced as the concentration increasing and the time prolonging, the effects to the latter were higher than those to the former, showing significant difference between them ( P <0.05 ). However, the effect of EGb761 was varied with the concentrations. EGb761 could promote T lymphocytes proliferation at low concentration but inhibit it at high concentration, there was a significant difference as compared with that in the control group ( all P < 0. 05). The apoptotic rate of T lymphocytes rose as the concentration of BN-52021 increasing (P < 0. 01). CONCLUSION: GBE has different effects on T lymphocytes proliferation since the different ingredients and the concentrations in vitro, and it also has different effects between healthy and asthmatic rats. Ginkgolide B is the main active ingredient among them, it can not only inhibit T lymphocytes proliferation but also increase the apoptotic rate.

[Effects of Shen-Mai injection on sternohyoid contractile properties in chronic intermittent hypoxia rat].

OBJECTIVE: To investigate the effect of Shen-Mai injection (SMI) on sternohyoid contractile properties in rats with chronic intermittent hypoxia. METHODS: Thirty healthy male SD rats were randomly assigned to three equal groups, the control group (A group), the chronic intermittent hypoxia group (B group) and the SMI group(C group). Rats in B group and C group were exposed to alternating periods of hypoxia and normoxia once per minute for 8 h/d for 5 weeks in order to mimic the intermittent hypoxia of obstructive sleep apnea-hypopnea syndrome (OSAHS) in humans. Isometric contractile properties were determined by electrostimulating the strips of isolated sternohyoid muscles at different frequencies (from 10 Hz to 100 Hz) to observe the changes of the sternohyoid contractile properties. RESULTS: (1) The tension of sternohyoid muscle in A group at different frequencies was (23.2 +/- 5.6), (26.2 +/- 5.0), (35.1 +/- 5.4), (46.0 +/- 8.5), (57.0 +/- 9.9), (69.9 +/- 9.7), (79.2 +/- 9.5), (85.7 +/- 7.6), (87.9 +/- 7.9), and (86.6 +/- 12.4) g/cm(2). The tension of sternohyoid muscle in B group [(19.5 +/- 4.7), (23.8 +/- 4.7), (33.0 +/- 5.1), (45.1 +/- 5.9), (54.2 +/- 7.0), (66.1 +/- 9.1), (74.2 +/- 9.1), (79.7 +/- 9.0), (82.0 +/- 8.4), and (80.7 +/- 11.8) g/cm(2)] was not significantly different from those in A group respectively (all P > 0.05); while the tension of sternohyoid muscle in C group [(30.5 +/- 2.3), (40.0 +/- 5.4), (56.2 +/- 7.6), (72.2 +/- 6.4), (82.0 +/- 5.5), (92.4 +/- 4.6), (98.1 +/- 4.0), (99.2 +/- 7.4), (101.8 +/- 3.9), and (102.2 +/- 4.0) g/cm(2)] was significantly different from those in B group respectively (all P < 0.05). (2) In fatigue test, the tension percentages of sternohyoid muscle in A group at 1, 2, 3, 4, and 5 min were (87.9 +/- 5.7)%, (72.1 +/- 11.5)%, (55.6 +/- 9.6)%, (39.7 +/- 10.7)%, (33.2 +/- 10.2)%. Compared with A group, the tension percentages of sternohyoid muscle in B group at 1, 2, 3, 4, and 5 min [(75.6 +/- 8.5)%, (41.6 +/- 7.3)%, (29.0 +/- 2.7)%, (20.4 +/- 2.9)%, (18.5 +/- 2.5)%, respectively] decreased significantly (all P < 0.05). Compared with B group, the tension percentages of sternohyoid muscle in C group [(87.9 +/- 4.4)%, (67.9 +/- 14.1)%, (48.4 +/- 9.9)%, (38.2 +/- 7.0)%, (33.8 +/- 9.3)%, respectively] increased significantly (all P < 0.05). CONCLUSIONS: Chronic intermittent hypoxia can increase upper airway muscle fatigue. SMI can significantly increase the contractile properties of upper airway muscle and resist the fatigue of upper airway muscle.

[Regulatory function of nuclear factor kappa B on lymphocyte proliferation and apoptosis in bronchial asthmatic rats and effect of triptolide on the regulation].

OBJECTIVE: To investigate whether nuclear factor kappa B (NF-kappa B) participates in the regulatory function of lymphocyte proliferation and apoptosis in bronchial asthma and whether the regulatory effect of triptolide on lymphocyte proliferation and apoptosis is conducted through NF-kappa B. METHODS: Intervention with dexamethasone, triptolide and PDTC, a NF-kappa B inhibitor, were used to treat astmatic rats respectively. Pathological examination, airway response were determined, the NF-kappa B P65 expression in lung tissue and splenic lymphocytes by immunofluorescent assay were adopted, proliferative cell nuclear antigen (PCNA) in splenic lymphocytes was measured by immunohistochemistry, apoptosis of splenic lymphocytes were monitored by flow cytometry and NF-kappa B activity was investigated by electrophoresis mobility shift assay (EMSA). RESULTS: The nuclear expression and DNA binding activity of lung tissue and splenic lymphocytes in asthmatic rats were all significantly higher than those in the control (all P < 0.05), so was the proliferation rate of splenic lymphocytes (P < 0.05), while the apoptosis rate was much lower than that of normal control (P < 0.05). Administration of PDTC could reduce the up-regulated expression and activity of NF-kappa B, the proliferation of splenic lymphocytes lowered, while the apoptosis increased. NF-kappa B activity showed an obviously positive correlation with proliferation of splenic lymphocytes (r = 0.89, P < 0.05) and a significantly negative correlation with apoptosis rate (r = -0.54, P < 0.05). After asthmatic rats had been treated with triptolide in vivo, the NF-kappa B nuclear expression and activity in airway and splenic lymphocytes, as well as the proliferation rate of splenic lymphocytes all lowered significantly (all P < 0.05), the apoptosis rate increased significantly (P < 0.05), at the same time, the inflammatory cell infiltration and high reactivity of airway were significantly alleviated (both P < 0.05). There were obviously positive correlation between the amount of airway eosinophils and reactivity with activity of NF-kappa B (r = 0.79 and r = 0.68, P < 0.05), which indicated that the effect of triptolide was not significantly different from that of dexamethasone (P > 0.05). CONCLUSION: (1) NF-kappa B participates the formation of airway inflammation and hyper-reactivity in asthmatic rats by positive regulation on proliferation and negative regulation on apoptosis of lymphocytes. (2) Triptolide reduces airway inflammation by way of inhibiting NF-kappa B, and further inhibiting the proliferation of lymphocytes, so that to give full play of the role of anti-asthmatic airway inflammatory agents. Whether the molecular mechanism of triptolide in inhibiting NF-kappa B simulates that of glucocorticoid needs further studying.

[Effect of Shen-Mai injection and aminophylline on diaphragmatic muscle cell apoptosis and related gene expression in rats with chronic hypoxia].

OBJECTIVE: To investigate the effect of Shen-Mai injection (SMI) and aminophylline on diaphragmatic muscle cell apoptosis and the Fas/FasL expression in chronic hypoxic rats. METHODS: Seventy-five male Wistar rats were randomly divided into three equal groups, control group (A group), SMI group (B group) and aminophylline group (C group). Then each group was further divided into five subgroups of pre-hypoxia, hypoxia 1 w, 2 w, 3 w and 4 w groups (5 rats each). The concentration of oxygen was (10 +/- 3)%, 7 d/w, 8 h/d for all groups, but only B group and C group received SMI (2 ml/d) and aminophylline (10 mg/kg) respectively. Apoptosis and Fas/FasL expression of diaphragmatic muscle cells were examined by the streptavidin biotin-peroxidase complex (SABC) immunohistochemistry techniques and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay, and Dunnett-t test was employed to compare the effects of SMI and aminophylline. RESULTS: (1) Fas, FasL expression in normal diaphragmatic muscle cells was very low with a positive rate of (2.77 +/- 0.45)% and (2.32 +/- 0.61)%. After hypoxia, the positive rates increased with the time of hypoxia time. SMI showed an inhibition on diaphragmatic muscle cell Fas and FasL expression;after hypoxia 1 w, 2 w, 3 w and 4 w, Fas expression [(6.36 +/- 4.17)%, (9.77 +/- 4.12)%, (18.02 +/- 6.91)% and (21.09 +/- 8.09)%] and FasL expression [(5.32 +/- 6.16)%, (9.58 +/- 3.79)%, (12.01 +/- 8.71)%, (19.43 +/- 10.31)%] in B group were different from those in A group respectively (all P < 0.05). But aminophylline did not show such an effect, the expression of Fas [(10.87 +/- 3.62)%, (24.13 +/- 3.79)%, (35.39 +/- 9.02)%, (39.56 +/- 10.12)%] and FasL [(9.37 +/- 4.07)%, (20.16 +/- 4.88)%, (31.81 +/- 7.07)%, (35.51 +/- 9.13)%] were not significantly different from those in A group respectively (all P > 0.05). (2) Diaphragmatic muscle cell apoptosis was very low in normal rats with a rate of (0.93 +/- 0.29)%, which also increased after hypoxia and the increase was associated with the time of hypoxia. Apoptosis rate was decreased by the administration of SMI, the rates of B group were (5.01 +/- 3.71)%, (9.37 +/- 3.12)%, (14.66 +/- 8.76)%, (18.16 +/- 7.02)%, respectively. Except for the first week, the differences of other weeks were all statistically significant when compared with A groups (all P < 0.05). But the effect of aminophylline was different, as compared to A group, only the apoptosis rate in hypoxia 4 w [(30.92 +/- 11.13)%] of C group being statistically significant different (P < 0.05). CONCLUSIONS: Fas and FasL participated in diaphragmatic muscle cell apoptosis in rats with chronic hypoxia. SMI showed a definite effect on the Fas and FasL protein expression and decreased diaphragmatic muscle cell apoptosis, which contributed to the therapeutic effect on diaphragmatic fatigue caused by hypoxia.