Effect of 11 beta OH pregna-1,4-diene-3,20-dione (delta HOP) on thymocyte plasma membranes.

The effect of delta HOP on the formation of concanavalin A (Con A) caps and steady state anisotropy (rs) obtained in 1,6-diphenyl-1,3,5-hexatriene (DPH) labeled thymocyte plasma membranes was compared with the effect of glucocorticoids on these experiments. Results demonstrate that delta HOP decreased cap formation "in vivo" as well as "in vitro" and that it did not change fluorescence anisotropy "in vitro". Glucocorticoids had an opposite effect, increasing fluidity apparently through a glucocorticoid specific mechanism not exerted by delta HOP.