Biochemical modulation of 5-fluorouracil with interferon α/β and γ on murine renal cell carcinoma

BACKGROUND: Conventional therapy for renal cell carcinoma (RCC) using interferon (IFN) has shown limited antitumor action. The purpose of the present study was to investigate the synergistic antitumor effects of IFN and 5-fluorouracil (5-FU) and to elucidate the mechanism underlying antitumor effects. METHODS: The antitumor effects and biochemical modulation of murine IFN and 5-FU were determined using murine renal cell carcinoma (RENCA). The activity of thymidylate synthase, thymidine kinase and the concentration of 5-FU incorporated into RNA was measured using cytosolic extracts of tumors. RESULTS: Triple combination therapy (5-FU, IFN alpha/beta and IFN gamma) showed a synergistic antitumor effect on RENCA tumors, because triple combination therapy suppressed growth significantly compared to combination therapy (IFN alpha/beta and IFN gamma, P = 0.0258) and 5-FU (P < 0.0001). Total thymidylate synthase was decreased by triple combination therapy (5-FU, IFN alpha/beta and IFN gamma, P = 0.0019) and combination therapy (5-FU and IFN gamma, P = 0.0018) compared to 5-FU alone. Thymidine kinase activity was decreased by triple combination therapy (5-FU, IFN alpha/beta and IFN gamma, P < 0.0001) and combination therapy (5-FU and IFN alpha/beta, P < 0.0001) compared to 5-FU alone. The concentration of 5-FU incorporated into RENCA tumors was increased by triple combination therapy (P = 0.0132) and combination therapy (5-FU and IFN alpha/beta, P = 0.0124) compared to 5-FU alone. CONCLUSIONS: Interferons alpha/beta and gamma showed different biochemical modulation for 5-FU. Therefore, combination therapy using 5-FU and IFN showed synergistic antitumor effects on murine RCC.     

Interferon alpha-2a shows antitumor activity in combination with 5-fluorouracil against human colon carcinoma xenografts: A study in reference to thymidylate synthetase activity inhibition

To clarify the mode of antitumor activity shown by a combination of recombinant human interferon alpha-2a (IFN) and 5-fluorouracil (5-FU), experimental therapy was performed on human colon carcinoma (Co-4) xenografts serially transplanted into nude mice, using IFN and 5-FU, either alone or in combination. IFN alone showed dose-dependent antitumor activity and 5-FU also revealed a moderate antitumor effect. Although IFN, given as 600,000 units/mouse daily sc×14, and 5-FU, given as 60 mg/kg q4d×3 ip, showed additive antitumor activity against Co-4, the thymidylate synthetase (TS) inhibition rate was unchanged in the tumors treated with the IFN/5-FU combination in comparison with those treated with 5-FU alone. This suggests that the antitumor activity of IFN and 5-FU in combination does not involve augmentation of the TS inhibition by 5-FU.     

The modulating effect of interferon alpha-2a on the antitumor activity of UFT against a human gastric carcinoma xenograft,SC-1-NU,in nude mice

The modulating effect of recombinant human interferon alpha-2a (IFN) on the antitumor activity of UFT, a mixed compound of tegafur and uracil at a molar ratio of 1:4, was investigated against SC-1-NU, a human gastric cancer xenograft serially transplanted in nude mice. IFN was administered subcutaneously at a dose of 60,000 IU/mouse daily for 14 days, and UFT was given at a dose of 15 mg/kg as tegafur daily, except on Sundays, for 3 weeks. The agents were administered either alone or simultaneously. Synergistic antitumor activity on SC-1-NU was produced by the combination of IFN and UFT without any increment of side effects, and the combination therapy also increased intratumoral thymidylate synthetase (TS) inhibition and the amount of 5-fluorouracil (5-FU) in the intratumoral RNA. Thus, IFN seems to modulate the antitumor activity of UFT against SC-1-NU through an inhibition of DNA synthesis and RNA distortion, and therefore this combination could be useful for clinical application.     

The modulation by L-leucovorin of 5-fluorouracil antitumor activity on human colon carcinoma cells in vitro and in vivo

We investigated the modulating effect of L-leucovorin (LV) on the antitumor effect of 5-fluorouracil (5-FU) against human colon carcinoma cells (C-1) in vitro and human colon carcinoma xenografts (Co-4) in nude mice. The modulating effect of LV on 5-FU reached an optimal concentration of 40–80 g/ml in vitro which was detected by a colorimetric MTT assay. An optimal dose of 200 mg/kg was also observed in the nude mouse system. The modulating effect of LV increased according to the increment of thymidylate synthetase inhibition in vivo. Since the pharmacokinetic pattern of LV in the nude mice administered LV at 200 mg/kg was similar to that in patients treated with LV at a dose of 100 mg/m², this clinical method of administration was thought to be adequate for modulating the antitumor activity of 5-FU against clinical colon carcinomas.     

Dendritic cell therapy in combination with interferon-α for the treatment of metastatic renal cell carcinoma

Objectives:   To evaluate the safety and efficacy of dendritic cell (DC) therapy in combination with interferon-α (IFN-α) in patients with advanced renal cell carcinoma.
Methods:   Seven patients, with progressive disease following IFN-α and interleukin (IL)-2 treatment, were treated with monocyte-derived DC (Mo-DC) and IFN-α between February 2004 and September 2006. They received Mo-DC once a week for 5 weeks and then every 2 weeks either intradermally or intratumorally. IFN-α (5–6 million U) was subcutaneously administered three times a week. Tumor size was evaluated by computed tomography scans before and after the 5th and 10th DC vaccination. A delayed-type hypersensitivity test was performed after the 4th and 5th DC administration for immunological monitoring.
Results:   Five patients had stable disease while the remaining two patients had progressive disease following 4 months of vaccination. In six patients the time to progression was prolonged in comparison with the previous cytokine treatment. Six patients showed delayed-type hypersensitivity after the 4th or 5th immunization. Three patients developed high fever following DC immunization. Treatment was associated with transient flu-like symptoms.
Conclusions:   Our data indicate that DC therapy combined with IFN-α is safe and has the potential for prolonging the time to progression in patients with advanced renal cell carcinoma.     

Effects of experimental chemoendocrine therapy with a combination of a pure antiestrogen and 5-fluorouracil on human breast cancer cells implanted in nude mice

The antitumor effects of an experimental chemoendocrine therapy combining a new pure antiestrogen ICI 182780 and 5-fluorouracil (5-FU) were studied on MCF-7 human breast cancer cells implanted in nude mice. ICI 182780 had a dose-dependent antitumor activity, which was potentiated by the concomitant use of 5-FU. When compared with the control group, the estrogen receptor (ER) level in the ICI 182780 group was lower and that in the combination group was markedly lower. Cell cycle analysis by flow cytometry (FCM) resulted in a lower percentage of S-phase cells (%S) in the treated mice. No significant difference was observed in the 5-FU concentrations in tumor cells, while the 5-FU content in RNA was significantly higher in the combination group. The changes in free thymidylate synthetase (TS) concentration indicated TS synthesis after the administration of 5-FU to be more greatly suppressed in the combination group than in the 5-FU group. These results suggest that ICI 182780 and 5-FU exert their combination effect mainly on ER-positive cells, and that the suppression of TS synthesis in tumor cells and the potentiation of the 5-FU-induced metabolic dysfunction of RNA are thus involved in the mode of action of this combination therapy. A summary of this paper was presented at the Fourth General Conference of the Japan Breast Cancer Society and the 34th General Meeting of the Japan Society for Cancer Therapy.     

Radiation-Induced Effects on Murine Kidney Tumor Cells: Role in the Interaction of Local Irradiation and Immunotherapy

Local tumor irradiation enhances the effect of interleukin-2 (IL-2) therapy in the Renca murine renal adenocarcinoma model. To investigate the mechanism(s) of this interaction, we studied the in vitro and in vivo effects of irradiation on the tumor cells. Tumor cells from in situ irradiated renal tumors had diminished proliferation in vitro. A similar growth inhibition was noted following injection of irradiated Renca cells into naive mice, but this effect could be overcome by injecting more cells. Histologic evaluation of tumors derived from irradiated cells revealed a decrease in mitosis and an increase in multinucleated giant cells, apoptosis and micronecrosis. The presence of irradiated tumor reduced the growth of nonirradiated tumor cells when both were injected into separate flanks of the same animal, suggesting that irradiated tumor cells may trigger a systemic antitumor response. Interleukin-2 therapy given after injection of irradiated tumor cells caused a significant increase in leukocytic infiltrates and micronecrosis. Our findings indicate that radiation directly affects tumor growth and induces a systemic mechanism which could be enhanced by IL-2.     

Type-I interferon receptor expression: Its circadian rhythm and downregulation after interferon-α administration in peripheral blood cells from renal cancer patients

Objectives:   To investigate the regulation of interferon-α (IFN-α) receptor expression in metastatic renal cell carcinoma (RCC) after IFN-α administration.
Methods:   Blood sampling was carried out in eight patients with metastatic RCC and six healthy volunteers. Flow-cytometric analysis using a monoclonal antibody against the active subunit of the type-I IFN-α receptor (IFNAR2) was carried out to examine the circadian rhythm of IFNAR2 expression in peripheral blood mononuclear cells (PBMC) as well as its downregulation after IFN-α administration.
Results:   According to its circadian rhythm IFNAR2 in PBMC had a peak expression at night. Once IFN-α is administered, IFNAR2 levels in PBMC showed downregulation within 48 h and recovered within another 48 h.
Conclusions:   Our findings might support the establishment of an optimal schedule for IFN-α administration.     

p16与细胞因子基因联合基因疗法对荷瘤小鼠免疫功能的影响

目的 探讨瘤体内直接注射途径的ｐ１６抑癌基因疗法与细胞因子（ＧＭ－ＣＳＦ）基因疗法联合应用对荷瘤肾癌小鼠免疫功能的影响。方法 建立皮下荷瘤肾癌小鼠模型。于接种种瘤细胞３ｄ后将荷瘤小鼠随机分为５组,分别给予不同的治疗,检测每组小鼠的免疫功能,观察每组小鼠的存活期,并行肿瘤病理学分析。结果 与其它４组相比,ｐ１６和ＧＭ－ＣＳＦ联合治疗组小鼠机体免疫功能显著增强（Ｐ〈０．０１）,存活时间明显延长（Ｐ〈０．０５）。结论 ｐ１６与ＧＭ－ＣＳＦ联合基因疗法的应用可增强小鼠抗肿瘤免疫反应,并抑制肿瘤的生长。     

Expression of angiostatin cDNA in a murine renal cell carcinoma suppresses tumor growth in vivo

Objectives. To investigate the effectiveness of angiostatin gene therapy for renal cancer using a mouse model. The generally poor prognosis of advanced renal cancer indicates the need for new therapeutic modalities. The dependency of solid tumor growth on angiogenesis suggests that antiangiogenic therapy would be effective against renal cell carcinoma, which is generally a hypervascular tumor.Methods. Murine renal cancer cells (Renca) transfected with murine angiostatin cDNA (AST-Renca) were subcutaneously implanted in BALB/c mice. Subsequently, the macroscopic appearance and volume of tumors were evaluated once per week. Renca cells transfected with empty plasmid DNA (mock-Renca) were used as a control. In addition, histologic sections of tumor were analyzed for neovascularization on the basis of an immunohistochemical analysis for CD31. The antitumor effect of AST-Renca on a parental Renca tumor at a distant site was also evaluated.Results. The mean volume of AST-Renca tumors was significantly less than that of the control vector-transfected tumors 3 weeks after implantation. In the cell proliferation assay, the expression of angiostatin did not inhibit the proliferation of Renca cells in vitro. Immunohistochemical analysis of neovascularization by staining with anti-CD31 antibody revealed that angiostatin suppressed tumor vessel formation. Moreover, implantation of AST-Renca inhibited the growth of parental Renca implanted simultaneously at a distant site.Conclusions. Expression of an angiostatin transgene can suppress the growth of murine renal cancer through the inhibition of tumor-induced angiogenesis. Angiostatin gene therapy may be effective against renal cancer.     

Interferon-b Inhibits Liver Metastases from Murine Colon 26 Carcinoma and its Highly Metastatic Variant

Purpose The antitumor effects of Interferon-β (IFN-β) are due to its direct inhibition of cell proliferation, immunostimulatory activity, and the inhibition of angiogenesis. We investigated the mechanism of the effects of IFN-β on a murine colon 26 cell line (CT 26) and its highly metastatic variant (L5). Methods We examined its inhibitory effects on cell proliferation in vitro and the development of liver metastases in vivo. Results The proliferation of CT 26 in vitro was inhibited by IFN-β in a dose- and time-dependent manner. The number of metastases was reduced in mice inoculated with CT 26 (P < 0.01) and L5 (P < 0.01) on Day 14 after treatment with IFN-β. The median survival rate of the mice inoculated with L5 administered IFN-β every other day, or every day was higher than in the control group (P < 0.05). A dorsal air sac assay demonstrated that IFN-β inhibited angiogenesis in mice inoculated with CT 26, but the effects disappeared with aminoguanidine, an inducible nitric oxide synthase inhibitor. Conclusion These results showed that IFN-β directly inhibits the proliferation of CT 26. In addition, the in vivo experiments suggested that IFN-β might effectively inhibit liver metastases.     

Treatment with Interferon-α-2b in Children with Life-Threatening Hemangiomas

BACKGROUND Childhood hemangiomas are benign tumors of endothelial cells, characterized by a rapidly proliferating initial phase and followed by a slow involution. However, some grow and may reach a massive size, threatening a patient's functions or life. These require immediate medical treatment.
OBJECTIVE The objective was to determine the therapeutic effectiveness of interferon (IFN)-α-2b in children with hemangiomas threatening the patient's functions or life.
MATERIALS AND METHODS All patients were treated with IFN-α-2b at a dosage of 3 million U/m² corporal surface, applied subcutaneously, 5 days a week for the first 6 months and subsequently three times a week for 6 to 24 months.
RESULTS The study included 20 patients with hemangiomas localized in different sites and with diverse functional alterations: ages varied between 3 and 48 months (median, 12.8 months), and 8 were male and 12 female. An excellent response was observed in 17 (85%) patients. Side effects were slight and transitory; there was a follow-up from 7 to 10 years, and no late toxicity was observed.
CONCLUSIONS We can conclude that IFN-α-2b is an effective option for treating alarming hemangiomas that are resistant to steroids and that endanger proper functioning of the affected organ or the patient's life.     

Tyrosine Kinase Inhibitor PTK/ZK Enhances the Antitumor Effects of Interferon-α/5-Fluorouracil Therapy for Hepatocellular Carcinoma Cells

Purpose

There is no standardized treatment for hepatocellular carcinoma (HCC) with portal vein tumor thrombus. We previously reported the efficacy of interferon-alpha and 5-fluorouracil combination (IFN/5-FU) therapy for these patients and the potential mechanism via the regulation of vascular endothelial growth factor (VEGF). In this study, we showed the VEGF-related effects of IFN/5-FU therapy using VEGF-receptor (VEGFR) selective inhibitor, PTK787/ZK222584 (PTK/ZK), in HCC cells.

Methods

Using two VEGF secreting and VEGFR expressing human HCC cell lines, PLC/PRF/5 and HuH7, we performed growth inhibitory assays in vitro and in vivo, apoptosis assay, cell cycle analysis, and Western blot analysis for the mechanism, with or without PTK/ZK in IFN/5-FU therapy.

Results

The combination of PTK/ZK and IFN/5-FU significantly inhibited cell growth in vitro and tended to reduce tumor growth in vivo in a HuH7 xenograft model in nude mice—in both cases without affecting VEGF secretion. PTK/ZK enhanced the IFN/5-FU induced apoptosis, based on increased proteins levels of Bax and reduced Bcl-xL and Bcl-2. Cell cycle analysis showed different results between the HCC cell lines following the combination therapy, possibly due to differences in p21 protein.

Conclusions

VEGF signaling inhibition would support an antitumor effect of IFN/5-FU therapy against HCC cell lines via induction of apoptosis and cell cycle delay.     

PTK787/ZK222584 Combined with Interferon Alpha and 5-Fluorouracil Synergistically Inhibits VEGF Signaling Pathway in Hepatocellular Carcinoma

Background

The prognosis of patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombus remains poor. We previously reported the beneficial effects of interferon alpha (IFN) and 5-fluorouracil (5-FU) combination therapy for these patients. We showed that the mechanism of therapy was regulation of vascular endothelial growth factor (VEGF). Here, we combined IFN/5-FU therapy with the VEGF receptor–selective inhibitor PTK787/ZK222584 (PTK/ZK) and examined the antitumor effects and the mechanism of action.

Methods

We studied two HCC cell lines, PLC/PRF/5 and HuH7, and a human umbilical vein endothelial cell line, HUVEC. We studied the effects of IFN/5-FU with or without PTK/ZK in growth inhibition assays, immunohistochemistry, Western blot analysis, and immunocytochemistry.

Results

In a HuH7 xenograft model, the combination of PTK/ZK and IFN/5-FU significantly inhibited proliferation, induced apoptosis, decreased microvessel density, reduced the number of tumor cells that expressed VEGF receptor 2 (VEGFR-2), and repressed the phosphorylation of Akt in vivo. In HCC cells and HUVECs in vitro, IFN/5-FU plus PTK/ZK repressed the expression of VEGFR-2 and repressed the phosphorylation of VEGFR, Akt, Erk, and p38MAPK.

Conclusions

VEGF signaling inhibition enhanced the antitumor effects of IFN/5-FU therapy on HCC cells and endothelial cells via Erk, Akt, and p38MAPK pathways.

     

Metastatic colorectal cancer: new therapeutics

NEED FOR NEW CHEMOTHERAPEUTIC AGENTS: The use of 5-FU in combination with leucoverin (LV) in the treatment of advanced colorectal cancer has consistently provided antitumoral response. The antitumoral activity of the 5-FU/LV combination is associated with inhibition of thymidylate synthetase, an essential enzyme in pyrimidine de novo biosynthesis of thymidilates as precursors of DNA synthesis. However, dose-limiting toxicities and the limited impact on survival point to the need to develop new drugs and approaches to improve therapeutic efficacy and survival. CLINICAL RESULTS: In advanced colorecal cancer, clinical results have confirmed the therapeutic efficacy of direct and indirect thymidylate synthetase inhibitors. Promising new agents: 5-FU prodrugs and inhibitors of dihydropyrimidine dehydrogenase (DPD) are promising chemotherapeutic agents with good oral bioavailability which can be combined with other drugs (leucoverin) with acceptable toxicity. Oxaliplatin and topoisomerase inhibitors such as irinotecan (CPT-11) have demonstrated activity in previously treated and newly diagnosed patients. COMBINATIONS: The best combination between DNA interaction drugs based on potentiation of DNA damage induced by thymidylate synthetase inhibitors and inhibition of DNA repair by DNA interactions remains to be evaluated.     

Interferon-β Is More Potent Than Interferon-α in Inhibition of Human Hepatocellular Carcinoma Cell Growth When Used Alone and in Combination With Anticancer Drugs

Background:The prognosis of advanced hepatocellular carcinoma (HCC) is extremely poor, but promising effects of chemotherapies combined with interferon (IFN) have been reported.Methods:To develop more effective combination therapies for HCC, we compared the antiproliferative effects of IFN- and IFN- in combination with various cytotoxic drugs on hepatoma cell lines using MTT assay and isobologram analysis.Results:IFN- was more potent than IFN- in inhibiting the cell growth of all cell lines (P < .05, two-way ANOVA). PLC/PRF/5 was more sensitive to either IFN, than HLE and HuH7. Cell growth of all cell lines was inhibited in a dose-dependent manner by 5-fluorouracil (5-FU), cisplatin (CDDP), and doxorubicin (DOX), but the sensitivities of these cells were considerably different. As for IFN-, synergistic effects were observed when combined with 5-FU and DOX on PLC/PRF/5 cells only, whereas IFN- showed synergistic effects with 5-FU and CDDP on HuH7 and PLC/PRF/5 cell lines.Conclusion:The spectra of the antiproliferative activity and synergistic effect of IFN- when combined with anticancer drugs are more potent than those of IFN-. Combinations of IFN- and anticancer drugs may provide a better treatment of HCC when combinations with IFN- are ineffective.Presented at the 56th Annual Cancer Symposium of the Society of Surgical Oncology, Los Angeles, California, March 5–9, 2003.     

Effects of danazol on DNA synthesis in rat prostate

Effects of danazol, an isoxazol derivative of the synthetic steroid 17α-ethinyltestosterone, on activities of thymidylate synthetase and thymidine kinase, which are the DNA-synthesizing enzymes included in de novo and salvage pathways of pyrimidine metabolism, respectively, were investigated in rat prostate. Danazol markedly reduced plasma levels of luteinizing hormone and testosterone, and organ weight, both enzyme activities and bro-modeoxyuridine-immunoreactive cells which were regarded as the S-phase cells in prostate. These results indicate that danazol shows a property as a potent antigonadotropin. © 1993 Wiley-Liss, Inc.     

Effect of 5-Fluorouracil plus Interferon on the Integrity of Colonic Anastomoses Covering with Fibrin Glue

Background It has been well established that the immediate postoperative intraperitoneal administration of chemotherapeutic agents such as 5-fluorouracil (5-FU) after curative colon resection for colon cancer destroys disseminated cancer cells and inhibits micrometastases but also inhibits anastomotic healing. On the other hand, the application of fibrin glue constitutes a physical barrier around the anastomosis and may prevent anastomotic leakage. The purpose of this experimental study was to determine the effect of 5-FU plus interferon (IFN)-α-2a on the integrity of colonic anastomoses covered with fibrin glue when injected intraperitoneally immediately after colon resection. Materials and Methods Sixty rats were randomized to one of four groups. After resection of a 1-cm segment of the transverse colon, an end-to-end sutured anastomosis was performed. Rats of the control and the fibrin glue groups were injected with 6 ml of 0.9% sodium chloride (NaCl) solution intraperitoneally. Rats in the 5-FU + IFN and the 5-FU + IFN + fibrin glue groups received 5-FU plus IFN intraperitoneally. The colonic anastomoses of the rats in the fibrin glue and in the 5-FU + IFN + fibrin glue groups were covered with fibrin glue. All rats were sacrificed on the 8th postoperative day, and the anastomoses were examined macroscopically. The bursting pressure measurements were recorded, and the anastomoses were graded histologically. Results Only the 5-FU + IFN group had anastomoses rupture, and the rupture rate (33%) in this group was significantly greater than in the other groups, where there were no ruptures (P = 0.015). The adhesion formations score was, on average, significantly higher in rats of the 5-FU + IFN group compared with the control group (P = 0.006) and the 5-FU + IFN + fibrin glue group (P = 0.010). Bursting pressures were significantly lower in the control group when compared to the fibrin glue and 5-FU + IFN + fibrin glue group (P < 0.001). Rats in the 5-FU + IFN + fibrin glue group developed significantly more marked neoangiogenesis than rats in the other groups. Inflammatory cell infiltration, collagen deposition, and fibroblast activity did not differ significantly among the four groups (P = 0.856, P = 0.192 and P = 0.243, respectively). Conclusion The immediate postoperative intraperitoneal administration of 5-FU plus IFN impairs colonic healing. However, when the colonic anastomoses were covered with fibrin glue, the injection of 5-FU plus IFN had no adverse effects on the integrity of the anastomoses.     

Isoflurane attenuates pulmonary interleukin-1β and systemic tumor necrosis factor-α following mechanical ventilation in healthy mice

Background: Mechanical ventilation (MV) induces an inflammatory response in healthy lungs. The resulting pro-inflammatory state is a risk factor for ventilator-induced lung injury and peripheral organ dysfunction. Isoflurane is known to have protective immunological effects on different organ systems. We tested the hypothesis that the MV-induced inflammatory response in healthy lungs is reduced by isoflurane.
Methods: Healthy C57BL6 mice ( n =34) were mechanically ventilated (tidal volume, 8 ml/kg; positive end-expiratory pressure, 4 cmH₂O; and fraction of inspired oxygen, 0.4) for 4 h under general anesthesia using a mix of ketamine, medetomidine and atropine (KMA). Animals were divided into four groups: (1) Unventilated control group; (2) MV group using KMA anesthesia; (3) MV group using KMA with 0.25 MAC isoflurane; (4) MV group using KMA with 0.75 MAC isoflurane. Cytokine levels were measured in lung homogenate and plasma. Leukocytes were counted in lung tissue.
Results: Lung homogenates: MV increased pro-inflammatory cytokines. In mice receiving KMA+ isoflurane 0.75 MAC, no significant increase in interleukin (IL)-1β was found compared with non-ventilated control mice.
Plasma: MV induced a systemic pro-inflammatory response. In mice anesthetized with KMA+ isoflurane (both 0.25 and 0.75 MAC), no significant increase in tumor necrosis factor (TNF)-α was found compared with non-ventilated control mice.
Conclusions: The present study is the first to show that isoflurane attenuates the pulmonary IL-1β and systemic TNF-α response following MV in healthy mice.