Peritoneal Macrophages and Neoplastic Cells

Abstract

The relationship between untreated, irradiated and heat-killed Ehrlich ascites cells and peritoneal macrophages was studied. At different time intervals, peritoneal washing fluids were observed with a dark field-equipped microscope and were used to prepare Leighton tubes. Histological preparations were made from mesenteric lymph nodes. While heat-killed cancer cells were immediately phagocytized by peritoneal macrophages, the phagocytosis of irradiated cancer cells started only after about 72 h. Pyroninophylic lymphoblasts in mesenteric lymph nodes appeared earlier in animals inoculated with heat-killed ascites cells. No phagocytosis by peritoneal macrophages and no histological modification in lymph nodes were observed in animals injected with untreated cancer cells. Mechanisms by which living homologous cancer cells can avoid phagocytosis by macrophages are discussed.

Synergystic Antitumor Effect of Polyphenolic Components of Water Soluble Derivative of Propolis against Ehrlich Ascites Tumour

“…Most of the MN cells in the peritoneal cavity were macrophages that are considered the major cells involved in tumour rejection. 21,34,39) However, in spite of the nonoccurrence of an increase in the number of MN cells, a significant increase was observed in the activity of peritoneal macrophages in test component-treated groups. It should also be pointed out that for the tumor-bearing group treated with test components, there was an increase in the median values of spreading percentage accompanying the increase in the test components cytotoxicity on EAT cells and in their effect on induction of apoptosis in tumor cells (Fig.…”

Avaliação dos efeitos do extrato etanólico, resíduo butanólico e resíduo aquoso de Pfaffia paniculata sobre o crescimento do tumor de Ehrlich em suas formas ascítica e sólida

“…paniculata (MATSUZAKI et al, 2003). NISTA, 1972;VORBRODT et al, 1973). Sabe-se que a morte celular pode ocorrer por mecanismos apoptóticos ou por mecanismos não apoptóticos, também denominados "oncose" (LEVIN et al, 1999, OKADA;MAK, 2004).…”

“…Estudos descritos na literatura demonstram que os macrófagos desempenham um importante papel no desenvolvimento tumoral (GOUGH et al, 2001). Além disso, sabe-se que macrófagos isolados de animais com tumor são capazes de lisar células tumorais, tanto in vivo quanto in vitro (EVANS;ALEXANDER, 1970;SEZZI, BELELLI, NISTA, 1972).…”

“…Foi demonstrado que os macrófagos podem fagocitar células tumorais previamente irradiadas ou mortas antes da inoculação intraperitoneal (SEZZI;BELELLI;NISTA, 1972;VORBRODT et al, 1973). Por outro lado, os macrófagos também podem favorecer a progressão tumoral, por exemplo, estimulando a neovascularização, ou liberando proteases na região tumoral, favorecendo a invasão (POLVERINI et al, 1977).…”