RESPONSES OF THE PLANARIAN Dugesia dorotocephala TO ULTRAVIOLET RADIATION OR PHOTOSENSITIZED TREATMENTS

Abstract— The survival of the planarian Dugesia dorotocephala was measured following treatment with germicidal ultraviolet (UV) radiation, with the DNA photosensitizer 8-methoxypsoralen (8-MOP) plus near UV radiation, or with the cytoplasm photosensitizer erythrosin plus visible radiation. The typical morphological response of an irradiated animal was lysis, with the head being the most sensitive part. All the survival curves had substantial shoulders. Treatments whose primary target was likely to be DNA (UV irradiation or 8-MOP plus near UV irradiation) resulted in lysis of part of the planarian population which commenced 24 h or more after treatment and continued over several days. The treatment whose primary target was likely to be the membranes of the planarian (erythrosin plus visible irradiation) resulted in lysis mostly during the first few hours after treatment. Thus an easily discerned endpoint, lysis, can be used for D. dorotocephala to evaluate photosensitizing compounds, where the kinetics of lysis may differentiate among compounds whose modes of action are different.     

CHEMILUMINESCENCE FROM THE REDUCTION OF AROMATIC AMINE CATIONS AND RUTHENIUM(III) CHELATES*,‡

Abstract— –Chemiluminescence is reported from two types of reactions; those involving the reduction of amine cations yield fluorescence amines: RN H₂^+m+ reductant → RN H₂+hv and those involving reduction of transition metal chelates where the reduced form of the chelate is fluorescent: ML_x⁺⁽ⁿ⁺¹⁾+ reductant →ML_x⁺ⁿ+hv The results reported here are for reduction of the cation radical of 1,6-diaminopyrene and ruthenium (III) chelates where chelate ligands are substituted 1,10-phenanthrolines or 2,2'-bipyridine. Reducing agents for 1,6-diaminopyrene were hydrazine or the naphthalene radical anion; for the ruthenium chelates either hydroxyl ion or hydrazine in acid solution. A detailed study is reported for the kinetics of the ruthenium (III)-hydrazine reaction, using a computer kinetic modeling program. A quantitative fit of the experimental data to computer-generated curves can be accomplished at low hydrazine concentrations. At higher hydrazine concentrations the correct qualitative shapes of curves can be generated but the quantitative fit is not exact.