THE EFFECTS OF HEMATOPORPHYRIN DERIVATIVES——PHOTOIRRADIATION ON DNA AND RNA SYNTHESES IN L1210 CELLS

The effects of hematoporphyrin derivatives (HPD) photoirradiation on DNA and RNA syntheses in L1210 cells were studied. The inhibition of ³H-TdR incorporation into DNA by HPD was significant, the IC₅₀ of HA 308, Jiguang 3, LF-019 and photofrin Ⅱ were 2.1, 2.5, 3.6 and >5 μ/ml, respectively. The synthesis of RNA (³H-UR incorporation) was also suppressed, the IC₅₀ for LF-019, Jiguang 3, HA 308, and Photofrin Ⅱ were 3.7, 5.7, 8.8 and >10 μg/ml, respectively. The photodynamic inactivation of DNA polymerase by hematoporphyrin derivative and light was noted.