Modifications of macrophage chemotaxis in rats bearing the transplantable tumour reticulosarcoma 'IRE'

Macrophage chemotactic activity was studied as a marker of the anti-inflammatory effect accompanying tumour growth. An inhibiting effect of the tumour on the macrophage mobility was observed by comparing the macrophages collected from normal rats and those from animals bearing the IRE reticulosarcoma. To explain these results, it is postulated that a MIF, or a similar inhibiting factor is released by the tumour. Both the the nature and function of such a factor(s) remain to be clarified.