Table 1

SAPK responses to nonreduced and reduced sphingolipid messengers

Treatmentp46-JNK1/p54-JNK2p38-RK
% Vehicle control
Vehicle100  ± 10100  ± 12
Ceramide697  ± 51-a 459  ± 611-a
Dihydroceramide98  ± 1299  ± 7
Sphingosine443  ± 391-a 427  ± 641-a
Dihydrosphingosine421  ± 551-a 440  ± 491-a

U937 cells were exposed to nonreduced (ceramide, sphingosine) and reduced (dihydroceramide, dihydrosphingosine) sphingolipid analogs at equimolar levels (10 μm). Cells were withdrawn after 10 min and prepared for in vitro assay of p46-JNK1/p54-JNK2 and p38-RK activities. Values are expressed as percentage of vehicle-treated controls and reflect mean ± standard error of triplicate determinations.

    • 1-a Increased vs.vehicle-treated control (p < 0.01).