Effect of VM-26 on the haematological responses of mice to L1210 leukaemia.

The haematological responses of BDF1 mice were monitored after i.v. or i.p. inoculation of L1210 leukaemic cells. Although a marked decrease in haematocrit was observed in mice given L1210 by either route, the anaemia was most pronounced after the i.p. route. The leucocyte count was more markedly increased after i.v. inoculation than after i.p. inoculation. The number of platelets decreased following either route, but was more depressed by i.v. inoculation. When mice were treated with VM-26 on Day 4 and i.p. inoculation of 10(6) L1210 cells, the haematological responses were altered. VM-26 prevented the accumulation of haemorrhagic ascites fluid and the precipitous decline in haemotacrit. However, the number of leucocytes increased dramatically, most significantly during the 48 h before death. VM-26 caused a temporary restoration of platelet count to near baseline levels. By the time of death, however, a second decrease in platelets had occurred. The results suggest that the haematological response of mice to L1210 leukaemic cells varies according to the route of inoculation, and that these tumour-induced haematological responses of the host can be modified by treatment with VM-26.