The hemolytic component of cancer anemia: effects of osmotic and metabolic stress on the erythrocytes of rats bearing multifocal inoculations of the Walker 256 tumor
Braz. j. med. biol. res
; 33(7): 815-22, July 2000.
Article
em En
| LILACS
| ID: lil-262681
Biblioteca responsável:
BR1.1
RESUMO
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.
Texto completo:
1
Temas:
Informacoes_doencas_cronicas_degenerativas
Base de dados:
LILACS
Assunto principal:
Fragilidade Osmótica
/
Hemoglobinas
/
Carcinoma 256 de Walker
/
Anemia Hemolítica
Idioma:
En
Revista:
Braz. j. med. biol. res
Assunto da revista:
BIOLOGIA
/
MEDICINA
Ano de publicação:
2000
Tipo de documento:
Article