Objectives: In this study, we aimed to investigate the effect of temperature on photosensitization of erythrocyte hemolysis by protoporphyrin. We also investigated absorption and fluorescence spectra of erythrocyte/protoporphyrin/human serum albumin system.
Material and Methods: Delayed photohemolysis measurements were made in photosensitized erythrocytes by protoporphyrin at irradiation temperatures from 5°C - 35°C and post-irradiation incubation temperatures from 5°C - 42°C. By measuring absorption and emission spectra of protoporphyrin on erythrocyte and human serum albumin (HSA) solutions, erythrocyte/protoporphyrin/HSA system was investigated.
Results: Delayed photohemolysis were accelerated at higher irradiation temperature and higher post-irradiation incubation temperature in photosensitized erythrocytes by protoporphyrin. By using spectrometric investigations, strong emission band at 632 nm and a weaker band near 700 nm were determined on erythrocyte/protoporphyrin/HSA system. A 648 photoproduct band was obtained when protoporphyrin was irradiated in the presence of HSA without erythrocyte and this band continued to decrease with increasing irradiation. The formation of the 648 nm band with HSA alone strongly suggests that protoporphyrin bound to erythrocyte reacts with HSA in the buffer.
Conclusion: Delayed photohemolysis rate were increased with the square of the light dose over this range of temperature. These temperature dependent photohemolysis curves are consistent with a kinetic model based on multihit target theory. The spectral and photohemolysis properties of the erythrocytes/protoporphyrin/HSA system have been of interest in connection with erythrocyte from erythropoietic porphyria patients.
Key Words: Protoporphyrin, Photosensitization, Human serum Albumin, Erythrocyte
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