Thiopyronine-sensitized photodynamic effect on cell growth, RNA and DNA synthesis of Chinese hamster ovary cells

Thiopyronine- and 8-methoxypsoralen-sensitized photodynamic effect on cell growth, colony forming ability and RNA synthesis in Saccharomyces mutants deficient in DNA repair

We compared the photodynamic effects of thiopyronine (TP) and visible light, and 8-methoxypsoralen (8-MOP) and ultraviolet A (UV-A) light, on growth, colony forming ability and RNA synthesis in a repair-proficient Saccharomyces strain and three mutants deficient in DNA repair mechanisms (DNA repair assays). With 8-MOP and UV-A repair-deficient mutants were significantly more sensitive than the repair-proficient strain indicating that the system is sensitive for the detection of DNA damage. With TP and visible light, the photodynamic effects were comparable in the mutants and the control, indicating no DNA damage. These results support previous work showing that the main target of TP photosensitization in eukaryotes is not nuclear DNA.

The effect of pentachlorophenol and its metabolite tetrachlorohydroquinone on cell growth and the induction of DNA damage in Chinese hamster ovary cells

It is shown that p-tetrachlorohydroquinone (TCH), the metabolite of the environmental chemical pentachlorophenol (PCP), is more toxic to cultured CHO cells than PCP, and that it causes DNA single-strand breaks and/or alkali-labile sites at concentrations of 2-10 microgram/ml as demonstrated by the alkaline elution technique.