Cytotoxic effects following micro-irradiation of cultured cells sensitized with haematoporphyrin derivative.

Haematoporphyrin derivative photosensitization has been studied in single heart cells in tissue culture by laser micro-irradiation (lambda = 632.8 nm). Changes of beating rate as well as cell death depend on the localization of the microbeam on the various parts of the cell. The results show that the targets for photodamage are the plasma membrane followed by the mitochondria.