Effect of the new theophylline derivative on leukocytes migration in vitro

New theophylline derivative: 7-beta-hydroxy-benzylopiperazinopropyl-theophylline (R6) has been investigated for its influence on spontaneous migration of leukocytes, as well as for their response to calcium ionophore A23187 and phytohemagglutinin (PHA). Leukocytes from the peripheral blood of healthy donors were used and migration developed according to the routine capillary method. It has been found that R6 inhibited migration most effectively if the cells have not been treated with other agents. An addition of R6 to media containing A23187 has slightly modified an original action exerted by ionophore itself, the final effect being dependent on calcium concentration in the medium. When R6 was applied simultaneously with PHA its effect on leukocyte migration was negligible, if however R6 was added to leukocytes previously pretreated with PHA--an ultimate increase in migration inhibition was observed. It is suggested that R6 inhibits both spontaneous locomotion of leukocytes and their response to stimulating agents acting via an increase in intracellular cAMP level and/or by hindering the calcium transport across cell membrane.