Neuronal injury after photoactivation of photofrin II.

摘要: Photodynamic therapy has been used in the management of patients with malignant brain tumors even though effects this form treatment on adjacent normal are incompletely characterized. The authors examined, sequential experiments, morphologic alterations affecting cerebral cortex rats injected Photophrin II and exposed to light. Initially, minimal cell alterations, including cisternal swelling both endoplasmic reticulum Golgi apparatus, involved only neurons located superficial layers These changes spread, over a period several hours, from surface bottom eventually entire cortical segment earliest structural signs lethal injury developed 18 hours after porphyrins had photoactivated astrocytes severely damaged. Signs included an increase number mitochondrial cristae appearance amorphous electron-dense deposits within swollen mitochondria. these was followed by segregation intracytoplasmic organelles fragmentation nuclear cytoplasmic membranes. tissue changes, those involving neurons, progressed coagulation necrosis at 48 hours. observations suggest that prophyrins (48 before photoactivation) cause astrocytes. This is neuronal necrosis, which appears two time intervals; initial occurs astrocytic disintegration. A second type alteration microvessels become thrombosed ischemia likely develop.