tacrolimus and pimagedine

Ischemia/reperfusion (I/R) injury is a main cause of primary dysfunction or non-function after liver transplantation (LTx). Recent evidence indicates that an increase in nitric oxide (NO) production after LTx is associated with I/R injury. The aim of this study was to demonstrate that low-dose FK506 in combination with aminoguanidine (AGH), which leads to a reduction of NO levels, has a protective effect by reducing I/R associated injury after LTx. Fortyone DA-(RT1av1) rats served as donors and recipients for syngenic orthotopic arterialised LTx. They were divided into 4 groups: controls without pre-/treatment (I), pre-/treatment with high-dose FK506 (II), pre-/treatment with AGH only (III), and pre-/treatment with low-dose FK506 in combination with AGH (IV). After LTx the laboratory parameters and liver biopsy were performed. The levels of transaminase (ALT) in groups I, II and III were significantly higher on day 3 after LTx compared to group IV (p = 0.001, p = 0.001, p = 0.000). In group IV the I/R-associated liver necrosis rate was reduced significantly. Our results demonstrated that a combined dual pharmacological pretreatment (group IV) reduced I/R injury of the graft after LTx in a rat model.

Topics: Animals; Dose-Response Relationship, Drug; Drug Therapy, Combination; Guanidines; Liver; Liver Transplantation; Nitric Oxide; Rats; Rats, Inbred Strains; Reperfusion Injury; Tacrolimus; Transplantation Conditioning

The aim of our study was to evaluate the efficacy of FK506, mycophenolate mofetil (MM) and aminoguanidine (AMG) on infiltration of macrophages (MPHs), neutrophils (NPHs) and dendritic cells (DC) into corneal grafts during the early phases after transplantation (Tx). Tx was performed in mice (C57BL/10 to BALB/c). Therapy included FK506 (0.2 mg/kg), MM (30 mg/kg) or AMG (0.1 g/kg), started at the day of Tx and was injected i.p. daily. Corneas were excised on the third and seventh day after Tx. Immunohistological evaluation using antibodies against MPHs, NPHs and DC was performed and corneal grafts were assessed in the periphery and in central part of the cornea separately. On the third day after Tx, a massive infiltration of MPHs and NPHs into corneal grafts was revealed; the DC infiltration was lower in all treated groups. Treatment with FK506 and MM led to a significant reduction of NPHs in the centers of the grafts, but not of MPHs. In contrast, AMG significantly reduced MPHs migration into allografts on the third day after Tx, whereas NPHs infiltration has not been attenuated. However, immunosuppressants had no influence on the infiltration of DC during early phases after Tx.

Topics: Animals; Cell Count; Cornea; Corneal Transplantation; Dendritic Cells; Female; Graft Rejection; Guanidines; Immunosuppressive Agents; Macrophages; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Models, Animal; Mycophenolic Acid; Neutrophil Infiltration; Neutrophils; Tacrolimus; Time Factors

The purpose of our study was to compare the effectiveness of immunosuppressive drugs on the prevention of allograft rejection in a murine model of low-risk and high-risk keratoplasty. The therapy included FK 506 (tacrolimus; 0.2 mg/kg), mycophenolate mofetil (30 mg/kg), aminoguanidine (0.1 g/kg), and combination of FK506 + mycophenolate mofetil or FK506 + aminoguanidine. The results obtained from the Gray's survival model stratified according to the type of subjects suggest that a major rejection risk reduction was achieved using FK506; good results also were obtained for mycophenolate mofetil. Although the point estimates of both the survival and relative risk of rejection suggest a deferred effect of the combination FK506 + mycophenolate mofetil, this finding did not prove statistically significant.

Topics: Animals; Corneal Diseases; Corneal Transplantation; Disease Models, Animal; Drug Combinations; Female; Graft Rejection; Graft Survival; Guanidines; Immunosuppressive Agents; Male; Mice; Mycophenolic Acid; Risk Factors; Tacrolimus; Transplantation, Homologous

It is reported that inducible nitric oxide synthase (iNOS) plays an important role in rejection. This study was designed to observe the expression of iNOS in the transplanted liver tissues and the effect of aminoguanidine(an inhibitor of iNOS) and FK506(immunosuppression) on acute rejection after liver transplantation.. All rats were divided into four groups: homogeneous (LEW-LEW), acute rejection (BN-LEW), aminoguanidine (BN-LEW), and FK506 (BN-LEW). In the last two groups the drugs were used in heterogeneous rats after liver transplantation. The expression of iNOS in liver tissues of all groups was investigated immunohistochemically.. In the acute rejection group, the expression of iNOS was extremely positive compared to the other three groups. The difference was statistically significant.. During the process of acute rejection in rat orthotopic liver transplantation, the enhanced expression of iNOS correlates to the severity of rejection. Aminoguanidine and FK506 can inhibit the expression of iNOS and palliate acute rejection.

Topics: Animals; Enzyme Inhibitors; Graft Rejection; Guanidines; Immunohistochemistry; Immunosuppressive Agents; Liver; Liver Transplantation; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Rats; Rats, Inbred BN; Rats, Inbred Lew; Severity of Illness Index; Tacrolimus

FK506 is an immunophilin-binding ligand that inhibits calcineurin and decreases nitric oxide (NO) production in the nervous tissues. We examined the effects in mice of systemic treatment with FK506 on the induction and expression of morphine (s.c.) tolerance and dependence and compared them with the effects of the non-specific NO synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), and specific inducible NO synthase inhibitor, aminoguanidine. FK506 (0.5-10 mg/kg, s.c.) exerted inhibitory effects on both development and expression of tolerance to morphine-induced antinociception. FK506 also significantly decreased the expression of morphine dependence, as assessed by naloxone-precipitated (2 mg/kg, i.p.) withdrawal syndrome, but a similar effect was not found for the development of morphine dependence. A similar pattern of effects was observed with L-NAME (3-20 mg/kg, i.p.), while aminoguanidine (50-100 mg/kg, i.p.) did not alter tolerance or dependence. Examining the possible interaction between their inhibitory effects on tolerance and dependence, we combined the subeffective doses of FK506 (0.5 or 1 mg/kg) with L-NAME (3 mg/kg) or aminoguanidine (100 mg/kg). The combination of FK506 with L-NAME, but not with aminoguanidine, significantly decreased the development and expression of tolerance and expression of dependence. These data show the effectiveness of FK506 on morphine tolerance and dependence and suggest an additive effect between FK506 and the inhibition of constitutive NO synthesis in this regard.

Topics: Analgesics; Animals; Dose-Response Relationship, Drug; Drug Tolerance; Enzyme Inhibitors; Guanidines; Immunophilins; Injections, Intraperitoneal; Injections, Subcutaneous; Ligands; Male; Mice; Morphine; Morphine Dependence; Naloxone; Narcotic Antagonists; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase; Pain Measurement; Substance Withdrawal Syndrome; Tacrolimus

Effects of endotoxemia-induced NO production on rat liver and hepatocytes in culture were investigated. Rats were treated intraperitoneally with saline, lipopolysaccharide (LPS, 10 mg/kg), L-nitroarginine methyl ester (L-NAME)+LPS, aminoguanidine (AG)+LPS, FK 506+LPS, S-nitroso-N-acetyl penicillamine (SNAP)+L-NAME+LPS and SNAP+FK 506+LPS. Mortality, hepatocyte viability and liver function test were estimated. Liver morphology was observed by light and electron microscopy. Hepatocyte cultures were treated with LPS, cytokine mixture (CM) with or without FK 506, L-NAME or AG. Hepatocyte function and inducible form of NOS (iNOS) expression were evaluated. Twenty-four hours after treatments with saline, LPS, L-NAME+LPS, AG+LPS, FK 506+LPS, SNAP+L-NAME+LPS and SNAP+FK 506+LPS, rat mortalities were 0%, 10%, 48%, 8%, 20%, 38% and 0%, and hepatocyte viabilities were 93+/-3%, 80+/-3%, 52+/-8%, 88+/-1%, 70+/-3%, 80+/-4% and 82+/-3%, respectively. AG+LPS or L-NAME+LPS administration was followed by excessive vacuolization of hepatocytes with lesions in the intermediary lobule zone characterized by features of secondary necrosis as a continuation of apoptotic processes. SNAP+L-NAME+LPS resulted in a well-preserved structure of central vein lobules with sparse signs of apoptosis. Treatment with LPS or CM increased iNOS expression in hepatocyte culture, which was inhibited by L-NAME, FK 506 or AG. AG reduced LPS-induced rise in alanine aminotransferase leakage. LPS-induced NO exerts cytoprotective effects in vivo, while LPS-induced NO in vitro appears to be toxic. Based on the data of this report, one cannot use in vitro results to predict in vivo responses to LPS-induced NO production. The pharmacological modulation of iNOS expression or NO production in vivo or in vitro, therefore, by the development of specific NO donors or inhibitors is promising for improvement of hepatocyte functions under the two experimental conditions, respectively.

Topics: Alanine Transaminase; Animals; Cell Survival; Cells, Cultured; Enzyme Inhibitors; Gene Expression Regulation, Enzymologic; Guanidines; Hepatocytes; Interferon-gamma; Interleukin-1; Lipopolysaccharides; Liver; Male; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Nitrites; Penicillamine; Rats; Rats, Wistar; RNA, Messenger; Tacrolimus; Tumor Necrosis Factor-alpha

The aim of this study was to compare the effectiveness of immunosuppressant FK 506 and the specific inhibitor of inducible nitric oxide synthase (iNOS) aminoguanidine (AG) in prevention of corneal graft rejection and to investigate the iNOS expression in the rejection process. Orthotopic corneal allografting in mice was performed (C57BL/10; H-2(b) to BALB/c; H-2(d)). FK 506 (0.3 mg/kg per day) or AG (100 mg/kg per day) was injected intraperitoneally for 4 weeks. Grafted mice without therapy served as controls. Immunohistological evaluation of iNOS-positive cells and macrophage infiltration in grafts 27th day after grafting was performed. Within 4 weeks FK 506 prevented graft rejection in 71% and AG in 57% of animals compared to 29% of clear grafts in controls. A significant proportion of iNOS-positive cells was detected in the rejected grafts of the control and AG-treated groups. The treatment with FK 506 resulted in the inhibition of iNOS expression to a high degree in the rejected corneas. Non-rejected corneas of all groups and non-transplanted corneas exhibited no iNOS-positive cells. A massive infiltration of macrophages was detected in the rejected grafts, whereas non-rejected grafts exhibited only slight infiltration of macrophages. The presented data suggest that overexpression of iNOS and/or activation of iNOS is one of the several influential factors that contribute to the rejection process and that iNOS suppression delays corneal allograft rejection. FK 506 and AG are effective drugs in preventing corneal allograft rejection. Higher beneficial effect of FK 506 on graft survival could be explained by its well-known selective T-cell immunosuppression.

Topics: Animals; Corneal Transplantation; Enzyme Inhibitors; Female; Graft Rejection; Graft Survival; Guanidines; Immunohistochemistry; Immunosuppressive Agents; Macrophages; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Tacrolimus

Systemically administered 3-nitropropionic acid (3-NPA) that inhibits the mitochondrial oxidative phosphorylation induces selective lesions in the striatum. To investigate the nature of these selective lesions, we administered 3-NPA (20 mg/kg, s.c. daily for 2 or 3 days) to Wistar rats and investigated the behavioral disturbance, striatal lesions and their variations after modulating the activity of nitric oxide synthase (NOS). On the second or third day of 3-NPA administration, half the animals manifested behavioral disturbances (paddling, rolling, tremor, abnormal gait, and recumbence). A strong extravasation of immunoglobulin G (IgG) and a decrease in immunoreaction for glial fibrillary acidic protein (GFAP) were detected, and iNOS-like (iNOS-L) immunoreactive small cells appeared in the lateral and central striatum especially around the vessels. A week later, lesions lacking GFAP-immunoreaction were detected in the striatum in survived animals. Pretreatment with N-nitro-L-arginine methyl ester (L-NAME) along with each injection of 3-NPA did not improve the behavioral disturbances nor the survival rate, but attenuated the extravasation of IgG and iNOS-L immunoreaction. Pretreatment with aminoguanidine or FK506 improved the behavioral symptoms and survival rate. Extravasation of IgG and expression of iNOS-L immunoreactivity were attenuated, and the striatal lesion was reduced. Data indicate the involvement of NO in the high vulnerability of the striatum, and that iNOS, one of inflammatory markers, is induced following exposure to 3-NPA.

Topics: Animals; Antihypertensive Agents; Astrocytes; Behavior, Animal; Cell Death; Dyspnea; Enzyme Inhibitors; Glial Fibrillary Acidic Protein; Guanidines; Immunohistochemistry; Immunosuppressive Agents; Injections, Subcutaneous; Male; Neostriatum; Neuritis; Neurotoxins; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Nitro Compounds; Propionates; Rats; Rats, Wistar; Tacrolimus