A morphological assessment of the stimulatory effect of coumarin on macrophages

In examining the migration of macrophages on to subcutaneously implanted coverslips in rats, it was found that coumarin (5-6 benzo-alpha-pyrone) and a preparation (Venalot) containing the former, very significantly increased the total macrophage number as well as the percentage of stimulation on the skin side of the coverslip. For the muscle side, Venalot increased the total numbers and the percentage stimulated while coumarin alone had no effect compared with the control. It remains to be seen whether these stimulated macrophages are also activated.