Ultrastructural changes induced in Walker carcinosarcoma by treatment with dihematoporphyrin ester and light in animals with diabetes mellitus

The purpose of this study was to evaluate by electron microscopy the tumoral fine structure changes induced by photodynamic therapy (PDT) in diabetic animals. Walker -256 carcinosarcoma harvested from animals with/without diabetes mellitus exposed to PDT (Photofrin II/5 mg/kg and 24 hrs later He-Ne laser irradiation/632.8 nm; 10 mW) and examined by electron microscopy showed different degrees of lesions in the nucleus and cytoplasmic fine structure. The ultrastructural changes induced by PDT in animals with diabetes mellitus bearing carcinosarcoma are characterized by: lysis of chromatin situated on the central zone of nucleus; swelling and vacuolization of mitochondria; formation of phagosome--like structures; myelin figures; degenerescence and disappearance of cytoplasmic organelles. Summing up, the data presented in this work demonstrate that the exposure to three doses of PDT produces changes in tumoral fine structure, increases survival rate and reduces incidence of carcinosarcoma in rats with diabetes mellitus.