Interleukin 1 protects hair follicles from cytarabine (ARA-C)-induced toxicity in vivo and in vitro.

ImuVert, a biologic response modifier, and interleukin 1 (IL 1) have been shown to protect the young rat from alopecia induced by cytarabine (ARA-C). In the present study the inhibition by ARA-C of DNA synthesis in hair follicles (HFs) and the protective effect of ImuVert and IL 1 were investigated in vivo and in vitro. Both ImuVert and IL 1 were equally effective in protecting rats from ARA-C-induced alopecia. DNA synthesis in HFs isolated from ARA-C-treated animals was 10-20% of untreated controls. Follicles isolated from animals given either ImuVert or IL 1 before ARA-C exhibited normal DNA synthesis. In vitro, the incubation of normal rat HF with ARA-C resulted in 80% inhibition of [3H]-thymidine uptake. Preincubation of the follicles for 1 hr with IL 1 before the addition of ARA-C completely blocked the inhibition. Preincubation with imuVert, however, was less effective in blocking the inhibition from ARA-C.