INDUCED EOSINOPENIA AND BASOPHILOPENIA BY »FREE« STEROIDS IN VITRO
ABSTRACT The in vivo mechanism of cortisone induced eosinopenia is disputed. Studies are presented which show in vitro eosinolysis in venous blood collected in sequestrine tubes with ethylenediamine tetra acetic acid as the anticoagulant. Free cortisol, cortisone and the synthetic anti-inflammatory analogues as well as Reichstein's Compound S were shown to be capable of inducing in vitro eosinopenia; the acetate and hemisuccinate salts of cortisol were inactive in vitro as were such compounds as deoxycorticosterone, 17α-hydroxyprogesterone, corticotrophin, heparin, epinephrine and acetylsalicylic acid. The speed of the reaction was roughly proportional to the concentration of cortisol in a range from 25 to 200 μg/100 ml. The ultimate degree of eosinolysis was not related to the amount of steroid. The eosinophils remaining after eosinolysis were resistant to further steroid.