[The role of peritoneal macrophages in realizing the growth inhibiting effect of glucocorticoids on reinoculated murine hepatoma 22 cells: the effect of hydrocortisone on the cytotoxic activity and metabolism of phospholipids by macrophages].
A single injection of hydrocortisone to rats with ascite hepatoma 22 had practically no effect on tumour growth. Inhibition of tumour growth was observed only after reinoculation of ascite hepatoma to mice that had received no less than 8 daily injections of the hormone. A single injection of hydrocortisone induced inhibition of the cytotoxic activity and decreased phospholipid metabolism in peritoneal macrophages. Contrariwise, long-term administration of the hormone caused marked activation of macrophage cytotoxicity. In this case incorporation of 32P into macrophage phospholipids was restored up to the control level. It is concluded that one of mechanisms underlying the inhibitory effect of glucocorticoids on macrophages is inhibition of phospholipid turnover. Presumably, long-term administration of the hormone promotes the formation of a new population of macrophages insensitive to the inhibitory effect of glucocorticoids and possessing a high cytostatic activity. The appearance of such activated macrophages may account for the enhancement of hydrocortisone effect on tumour cells upon prolonged administration of the hormone.
Krasil'nikov
M A
MA
Khramtsova
S N
SN
Basiuk
E I
EI
D000818:Animals; D003602:Cytotoxicity, Immunologic; D004273:DNA, Neoplasm / Q000378:metabolism; D005938:Glucocorticoids / Q000494:pharmacology*; D008114:Liver Neoplasms, Experimental / Q000473:pathology*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D010529:Peritoneal Cavity / Q000166:cytology; D010743:Phospholipids / Q000378:metabolism*; D013936:Thymidine / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects*
D004273:DNA, Neoplasm; D005938:Glucocorticoids; D010743:Phospholipids; D013936:Thymidine
Rol' peritoneal'nykh makrofagov v realizatsii rost-ingibiruiushchego deĭstviia gliukokortikoidov na kletki perevivaemoĭ myshinoĭ gepatoma 22: vliianie gidrokortizona na tsitotoksicheskuiu aktivnost' i obmen fosfolipidov makrofagov.