The influence of in vivo pretreatment of cyclophosphamide on phagocytic activity of mouse macrophages in vitro.

The action of cyclophosphamide on phagocytosis by macrophages from mouse peritoneal exudate cultured in vitro was studied. The mice were pretreated with cyclophosphamide administered for seven days. The experiments were carried out in the presence of serum (with or without complement) from untreated animals or without serum. A significantly increased phagocytic activity was shown in experiments without serum and when decomplemented serum was used. No significant variation was found when macrophages from treated mice were tested with serum with complement from untreated animals. It is tentatively assumed that low dosage administration in vivo of cyclophosphamide does not affect macrophage phagocytic activity while several findings suggest an inhibitory effect of cyclophosphamide on T and B lymphocytes.