Inactivation of bladder tumor cells and enzymes by methylene blue plus light

Using a cystoscopic light source and methylene blue as the sensitizing dye, photoactivation was examined in two types of experiments. In the first, the in vitro study destruction of two enzymes (glucose-6-phosphate dehydrogenase and lactic dehydrogenase) was examined in suspensions of whole and homogenized tumor cells from a transplantable bladder tumor. In the second or in vivo study rats were used to demonstrate that tumor cell suspensions treated with methylene blue plus light, when inoculated into susceptible rats, failed to "take" and produce new tumors. These experiments suggest a possible therapeutic use in treatment of human bladder tumors, though further study would be required.