RESUMO
BACKGROUND: The purpose of this study was to investigate the effect of infliximab, an anti-tumor necrosis factor α (TNFα) monoclonal antibody, on the progression of cachexia and several metabolic parameters affected by the Walker-256 tumor in rats. METHODS: Infliximab (0.5 mg/kg) was ip administered, twice a day, beginning at the day in which the Walker-256 tumor cells were inoculated. After 12 days of treatment, the tumor growth, some parameters of cachexia/anorexia, the blood levels of triacylglycerol, glucose, lactate and urea, the peripheral response to insulin and the hepatic glycolysis and gluconeogenesis were investigated. The peripheral response to insulin was evaluated by the insulin tolerance test and the glycolysis and gluconeogenesis in isolated perfused liver. RESULTS: The treatment with infliximab did not alter the growth of the Walker-256 tumor, but attenuated (p < 0.05) the reduction of body weight and prevented (p < 0.05) the loss of retroperitoneal adipose tissue induced by the tumor. Moreover, treatment with infliximab tended to minimize the loss of gastrocnemius muscle, the reduction in food intake, the peripheral response to insulin and the liver gluconeogenesis from alanine, as well as the increased blood triacylglycerol, caused by the tumor. In contrast, treatment with infliximab did not attenuate the reduction in hepatic glycolysis and glycemia, nor did it minimize the rise in blood levels of lactate and urea induced by the tumor. CONCLUSION: The treatment with infliximab ameliorated some changes associated with cachexia, such as the reduction of adipose tissue and body weight, suggesting that TNFα plays a significant role in mediating these changes induced by the tumor. In addition, infliximab tended to improve or had no effect on other metabolic parameters affected by the Walker-256 tumor, suggesting that other mediators or tumor-related events are involved in these disorders.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Anticorpos Monoclonais/farmacologia , Caquexia/tratamento farmacológico , Carcinoma 256 de Walker/tratamento farmacológico , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Glicemia/efeitos dos fármacos , Caquexia/sangue , Caquexia/complicações , Carcinoma 256 de Walker/sangue , Carcinoma 256 de Walker/complicações , Ingestão de Alimentos/efeitos dos fármacos , Gluconeogênese/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Infliximab , Ácido Láctico/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Ratos , Triglicerídeos/sangue , Ureia/sangueRESUMO
BACKGROUND: Many mushrooms have been used since ancient times for their nutritional and therapeutic properties. Alterations of hematologic parameters are commonly observed in patients with cancer, mainly due to the presence of some inflammatory mediators that have hemolytic effects, and yet can stimulate white blood cell release. Abnormalities in biochemical parameters are also found due to alterations in carbohydrate, protein, and lipid metabolism. OBJECTIVE: The aim of the present study was to evaluate the effects of Agaricus sylvaticus on hematologic and biochemical parameters of rats inoculated with Walker 256 tumor. METHODS: The animals were divided into 4 groups, with 20 in each group. Group 1 was inoculated with Walker 256 tumor and treated with A. sylvaticus. Group 2 was inoculated with Walker 256 tumor and administered a placebo solution. Group 3 was not inoculated with the tumor and was treated with A. sylvaticus, and Group 4 was not inoculated with the tumor and was administered a placebo solution. The rats were sacrificed after 12 days of treatment, and blood was collected following heart sectioning. RESULTS: Statistically significant differences between Groups 1 and 2 were observed in red blood cell count, hematocrit, hemoglobin, C-reactive protein, urea, and triglyceride levels. No significant differences between these two groups were noted in hematimetric indices, leukocyte counts, creatinine, and glucose levels. No significant differences in hematologic and biochemical parameters were noted between Groups 3 and 4. CONCLUSION: A. sylvaticus is able to reduce anemia and improve biochemical parameters in animals with cancer and has no adverse effects on the blood cells of healthy animals.
Assuntos
Agaricus , Anemia/tratamento farmacológico , Carcinoma 256 de Walker/complicações , Suplementos Nutricionais/efeitos adversos , Anemia/sangue , Anemia/etiologia , Animais , Análise Química do Sangue , Carcinoma 256 de Walker/sangue , Carcinoma 256 de Walker/metabolismo , Testes Hematológicos , Masculino , RatosRESUMO
Studies on fatty acid and amino acid metabolism in the liver of Walker-256 tumour-bearing rats have revealed several changes. Comparisons, however, have been based on experiments performed with non-physiological, frequently unrealistic, substrate concentrations. The aim of the present work was to examine the influence of physiological substrate concentrations on gluconeogenesis, ketogenesis and related parameters. Isolated livers were perfused and substrates were infused at concentrations that were reported to occur in healthy and tumour-bearing rats. Ketogenesis and the mitochondrial NADH/NAD+ ratio were smaller in the tumour-bearing condition at low (0.2 mM) and high (0.8 mM) oleate concentrations. In the absence of oleate, gluconeogenesis from alanine (0.7 mM) and gluconeogenesis plus the associated changes in oxygen uptake due to lactate/pyruvate (2/0.2 and 6/0.3 mM) were smaller in livers of tumour-bearing rats. However, the response of gluconeogenesis from lactate/pyruvate in livers of tumour-bearing rats to 0.8 mM oleate was more pronounced so that a trend towards normalization was apparent at high substrate and oleate concentrations. Gluconeogenesis from 0.7 mM alanine was not significantly changed by oleate in the tumour-bearing state; in the control condition, stimulation occurred at 0.2 mM oleate and inhibition at 0.8 mM oleate. This diminution almost equalized the hepatic alanine-dependent gluconeogenesis of both control and tumour-bearing rats. Ureogenesis was smaller in the tumour-bearing state and was not affected by oleate. It was concluded that the high concentrations of fatty acids and lactate/pyruvate, which predominate in rats bearing the Walker-256 tumour, could be effective in normalizing the gluconeogenic response of livers from tumour-bearing rats.
Assuntos
Carcinoma 256 de Walker/metabolismo , Ácidos Graxos/sangue , Neoplasias Hepáticas Experimentais/metabolismo , Fígado/metabolismo , Animais , Carcinoma 256 de Walker/sangue , Gluconeogênese/fisiologia , Ácido Láctico/sangue , Neoplasias Hepáticas Experimentais/sangue , Masculino , Ácido Oleico/metabolismo , Ratos , Ratos WistarRESUMO
Two variants of this Walker 256 tumor have been previously reported as Walker 256 A and variant AR. The variant A has more aggressive property than variant AR and can induce systemic effects such as anorexia, sodium and water retention, followed by weight loss and death. The mechanisms involved in enhancing tumor regression and progression in this model are still incompletely understood. In the present study, serum and spleen mononuclear cells and tumor cells from animals inoculated with variants A and AR, were isolated to investigate the TGF-beta, IL-12, IFN-gamma and TNF-alpha and relationship with anemia, weight of animals, weight of spleen, volume of tumor and osmotic fragility compared with controls inoculated with Ringer Lactate. Results demonstrate that the group inoculated with variant A, compared to variant AR, shows high levels of TGF-beta gene expression in both tumor tissue and spleen cells, no expression of IFN-gamma and a progressive and higher levels of IL-12 in tumor tissue without inflammatory infiltrate visualized by optical microscopy. These results suggest that the aggressively of variant A is relate to cytokine modulation, facilitating the growth and escape of tumor cells. Furthermore, IL-12 seems to be constitutively expressed in both tumor lineage A and AR.
Assuntos
Carcinoma 256 de Walker/genética , Citocinas/genética , Anemia/sangue , Anemia/genética , Anemia/patologia , Animais , Peso Corporal , Carcinoma 256 de Walker/sangue , Carcinoma 256 de Walker/patologia , Citocinas/sangue , Ensaio de Imunoadsorção Enzimática , Expressão Gênica , Hemoglobinas/análise , Interferon gama/sangue , Interferon gama/genética , Interleucina-12/genética , Masculino , Tamanho do Órgão , Fragilidade Osmótica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Baço/metabolismo , Baço/patologia , Fator de Crescimento Transformador beta/sangue , Fator de Crescimento Transformador beta/genética , Fator de Necrose Tumoral alfa/genéticaRESUMO
Extracellular adenine nucleotide hydrolysis in the circulation is mediated by the action of an NTPDase (CD39, apyrase) and of a 5'-nucleotidase (CD73), presenting as a final product, adenosine. Among other properties described for adenine nucleotides, an anti-cancer activity is suggested, since ATP is considered a cytotoxic molecule in several tumour cell systems. Conversely, some studies demonstrate that adenosine presents a tumour-promoting activity. In this study, we evaluated the pattern of adenine nucleotide hydrolysis by serum and platelets from rats submitted to the Walker 256 tumour model. Extracellular adenine nucleotide hydrolysis by blood serum and platelets obtained from rats at, 6, 10 and 15 days after the subcutaneous Walker 256 tumour inoculation, was evaluated. Our results demonstrate a significant reduction in ATP, ADP and AMP hydrolysis in blood serum at 6, 10 and 15 days after tumour induction. In platelets, a significant reduction in ATP and AMP hydrolysis was observed at 10 and 15 days after tumour induction, while an inhibition of ADP hydrolysis was observed at all times studied. Based on these results, it is possible to suggest a physiologic protection mechanism against the tumoral process in circulation. The inhibition in nucleotide hydrolysis observed probably maintains ATP levels elevated (cytotoxic compound) and, at the same time, reduces the adenosine production (tumour-promoting molecule) in the circulation.
Assuntos
Nucleotídeos de Adenina/metabolismo , Plaquetas/metabolismo , Carcinoma 256 de Walker/sangue , Soro/metabolismo , Nucleotídeos de Adenina/antagonistas & inibidores , Animais , Plaquetas/enzimologia , Carcinoma 256 de Walker/enzimologia , Hidrólise , Pirofosfatases/sangue , Ratos , Soro/enzimologia , Células Tumorais CultivadasRESUMO
Two variants (A and B) of the widely employed Walker 256 rat tumor cells are known. When inoculated sc, the A variant produces solid, invasive, highly metastasizing tumors that cause severe systemic effects and death. We have obtained a regressive variant (AR) whose sc growth is slower, resulting in 70-80% regression followed by development of immunity against A and AR variants. Simultaneously with the beginning of tumor regression, a temporary anemia developed (approximately 8 days duration), accompanied by marked splenomegaly (approximately 300%) and changes in red blood cell osmotic fragility, with mean corpuscular fragility increasing from 4.1 to 6.5 g/l NaCl. The possibility was raised that plasma factors associated with the immune response induced these changes. In the present study, we identify and compare the osmotic fragility increasing activity of plasma fractions obtained from A and AR tumor bearers at different stages of tumor development. The results showed that by day 4 compounds precipitating in 60% (NH4)2SO4 and able to increase red blood cell osmotic fragility appeared in the plasma of A and AR tumor bearers. Later, these compounds disappeared from the plasma of A tumor bearers but slightly increased in the plasma of AR tumor bearers. Furthermore, by day 10, compounds precipitating between 60 and 80% (NH4)2SO4 and with similar effects appeared only in plasma of AR tumor bearers. The salt solubility, production kinetics and hemolytic activity of these compounds resemble those of the immunoglobulins. This, together with their preferential increase in rats bearing the AR variant, suggest their association with an immune response against this tumor.
Assuntos
Carcinoma 256 de Walker/sangue , Fragilidade Osmótica , Plasma , Anemia/etiologia , Animais , Plasma/química , Ratos , Fatores de TempoRESUMO
Cancer anemia is classified as an anemia of chronic diseases, although it is sometimes the first symptom of cancer. Cancer anemia includes a hemolytic component, important in the terminal stage when even transfused cells are rapidly destroyed. The presence of a chronic component and the terminal complications of the illness limit studies of the hemolytic component. A multifocal model of tumor growth was used here to simulate the terminal metastatic dissemination stage (several simultaneous inoculations of Walker 256 cells). The hemolytic component of anemia began 3-4 days after inoculation in 100% of the rats and progressed rapidly thereafter: Hb levels dropped from 14.9 +/- 0.02 to 8.7 +/- 0.06 from days 7 to 11 ( approximately 5 times the physiologically normal rate in rats) in the absence of bleeding. The development of anemia was correlated (r2 = 0.86) with the development of other systemic effects such as anorexia. There was a significant decrease in the osmotic fragility of circulating erythrocytes: the NaCl concentration causing 50% lysis was reduced from 4.52 +/- 0.06 to 4.10 +/- 0.01 (P<0.01) on day 7, indicating a reduction in erythrocyte volume. However, with mild metabolic stress (4-h incubation at 37oC), the erythrocytes showed a greater increase in osmotic fragility than the controls, suggesting marked alteration of erythrocyte homeostasis. These effects may be due to primary plasma membrane alterations (transport and/or permeability) and/or may be secondary to metabolic changes. This multifocal model is adequate for studying the hemolytic component of cancer anemia since it is rapid, highly reproducible and causes minimal animal suffering.
Assuntos
Anemia Hemolítica/etiologia , Carcinoma 256 de Walker/sangue , Hemoglobinas/metabolismo , Análise de Variância , Anemia Hemolítica/sangue , Animais , Anorexia/etiologia , Carcinoma 256 de Walker/induzido quimicamente , Doença Crônica , Modelos Animais de Doenças , Masculino , Transplante de Neoplasias , Fragilidade Osmótica , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Cancer anemia is classified as an anemia of chronic diseases, although it is sometimes the first symptom of cancer. Cancer anemia includes a hemolytic component, important in the terminal stage when even transfused cells are rapidly destroyed. The presence of a chronic component and the terminal complications of the illness limit studies of the hemolytic component. A multifocal model of tumor growth was used here to simulate the terminal metastatic dissemination stage (several simultaneous inoculations of Walker 256 cells). The hemolytic component of anemia began 3-4 days after inoculation in 100 percent of the rats and progressed rapidly thereafter: Hb levels dropped from 14.9 +/- 0.02 to 8.7 +/- 0.06 from days 7 to 11 (~5 times the physiologically normal rate in rats) in the absence of bleeding. The development of anemia was correlated (r2 = 0.86) with the development of other systemic effects such as anorexia. There was a significant decrease in the osmotic fragility of circulating erythrocytes: the NaCl concentration causing 50 percent lysis was reduced from 4.52 +/- 0.06 to 4.10 +/- 0.01 (P<0.01) on day 7, indicating a reduction in erythrocyte volume. However, with mild metabolic stress (4-h incubation at 37§C), the erythrocytes showed a greater increase in osmotic fragility than the controls, suggesting marked alteration of erythrocyte homeostasis. These effects may be due to primary plasma membrane alterations (transport and/or permeability) and/or may be secondary to metabolic changes. This multifocal model is adequate for studying the hemolytic component of cancer anemia since it is rapid, highly reproducible and causes minimal animal suffering.
Assuntos
Animais , Masculino , Ratos , Anemia Hemolítica/etiologia , Carcinoma 256 de Walker/sangue , Carcinoma 256 de Walker/metabolismo , Hemoglobinas/metabolismo , Fragilidade Osmótica , Análise de Variância , Anemia Hemolítica/metabolismo , Anemia Hemolítica/patologia , Anorexia/etiologia , Carcinoma 256 de Walker/induzido quimicamente , Doença Crônica , Modelos Animais de Doenças , Transplante de Neoplasias , Ratos WistarRESUMO
Activation of lymphocytes and macrophages by the implantation of tumour cells (10(7) cells per rat) into the left flank of rats increased the conversion of glucose to lactate and of glutamine to glutamate and aspartate and the decarboxylation of [U-14C]-glucose and [U-14C]-glutamine in incubated cells. In addition, the amount of GLUT1 was increased in macrophages. The effect of insulin treatment on glucose and glutamine metabolism of lymphocytes and macrophages activated by Walker 256 tumour implantation was also examined. For this purpose, insulin was injected subcutaneously (4 U/100 g b.w. daily) after the fourth day of tumour implantation and the rats were killed 10 days afterwards. Insulin treatment fully reverted the changes due to tumour implantation in the metabolism of glucose and glutamine in lymphocytes and of glucose in macrophages.
Assuntos
Glicemia/metabolismo , Glutamina/sangue , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Linfócitos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Animais , Radioisótopos de Carbono , Carcinoma 256 de Walker/sangue , Carcinoma 256 de Walker/patologia , Transportador de Glucose Tipo 1 , Ácido Glutâmico/sangue , Ácido Láctico/sangue , Ativação Linfocitária , Linfócitos/metabolismo , Macrófagos/metabolismo , Masculino , Proteínas de Transporte de Monossacarídeos/sangue , Transplante de Neoplasias , Ratos , Ratos WistarRESUMO
The oxidation of fatty acids in lymphocytes from the mesenteric lymph nodes of Walker 256 carcinosarcoma-bearing rats (TB) was studied, as well as the activity of the mitochondrial long-chain fatty acid transport system. Two-month old Wistar rats were subcutaneously implanted with 10(7) cells and after 2 weeks the tumor mass was 15-20 per cent of the carcass weight. The activity of camitine palmitoyltransferase (CPT) II was demonstrable in the lymphocytes of the TB group (8.2 ñ 5.6 nmol/min per mg mitochondria protein for 15 rats) and was not detected in the control, while that of CPT I was only slightly increased in the former. Similar rates of [1-14C]-palmitate decarboxylation were found for TB and control rat lymphocytes. However, when the rate of decarboxylation of [1-14C]-paimitate present in the intracellular pool of lipids was investigated in cultured lymphocytes, the cells of TB rats exhibited rates 17-fold higher than those of control animals in the presence of fetal calf serum (FCS). Decarboxylation in the presence of TB rat serum was 178-fold higher than obtained with normal rat serum, and 1.4-fold compared to FCS. These results suggest that, during cachexia, lymphocytes preferably oxidize intracellular lipids, and that this capacity is greatly enhanced by factors circulating in the serum of tumor-bearing rats.