Toluidine blue: the mode of photodynamic action in yeast cells.

摘要: — Toluidine blue, a thiazine dye, was shown to have in vivo photodynamic activity through singlet oxygen (O21Δg) production. This based mainly on the effective protection by N-3 and marked enhancement D2O for sensitized inactivation of yeast cells. The mode was, however, quite different from that acridine orange, which mechanism has also been proposed. most characteristic feature toluidine blue-sensitization total lack induction gene conversion (at trp 5), while survival went down below 10%. non-induction genetic changes confirmed at several pH's neutral region, whereas seen parallel reported pH dependence production vitro. Direct measurements microspectrophotometry showed none blue accumulated cell. It ascertained acridine-sensitized never interfered with binding orange cellular DNA. These findings suggested unique is attributable its action outside Furthermore, comparisons between photodynamically treated cells (with blue) non-treated respect response UV irradiation excluded certain cell functions relating expression possible damage sites. photo-reactivation process induced not disturbed pre-toluidine sensitition. In view foregoing results, plasma membrane tentatively as likely site damage.