Effects of m-aminobenzamide on the response of Chinese hamster cells to hyperthermia and/or radiation.
The modifying effects of m-aminobenzamide (m-ABA), an inhibitor of poly(ADP-ribose) synthesis, on 42 degrees C hyperthermia- and/or radiation-induced cell killing were examined in Chinese hamster V-79 cells. When cells were exposed to 42 degrees C hyperthermia in combination with m-ABA (10 mM), cell survival decreased compared with that for 42 degrees C hyperthermia alone. Thermosensitizing effects of m-ABA changed with treatments in a decreasing order of during and after heating greater than during heating greater than after heating. Treatments with m-ABA during and/or after X irradiation enhanced radiation-induced cell killing. When cells were exposed to combined treatment with X irradiation, 42 degrees C hyperthermia (60 min), and m-ABA (24 hr), cell survival decreased markedly compared with that for X irradiation alone. However, with both X----42 degrees C and X----42 degrees C----m-ABA, the enhancement ratios (ER), designated as D0 ratio, were similar. These results suggest that the mechanisms of radiosensitization by m-ABA may be similar to those of 42 degrees C hyperthermia.
D000818:Animals; D001549:Benzamides / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D006224:Cricetinae; D003412:Cricetulus; D004307:Dose-Response Relationship, Radiation; D005347:Fibroblasts / Q000187:drug effects / Q000528:radiation effects*; D006358:Hot Temperature; D011064:Poly Adenosine Diphosphate Ribose / Q000096:biosynthesis; D011836:Radiation Tolerance / Q000187:drug effects
D001549:Benzamides; D011064:Poly Adenosine Diphosphate Ribose; C025160:3-aminobenzamide