Pathological Experimental Study Of Bladder Cancer Internal Radiation By 5-[～(125)I]iodo-2'-deoxyuridine

Objective: To investigate the distribution of radioactivity after intravesical instillation of 5-[¹²⁵I]iodo-2'-deoxyuridine (¹²⁵I-UdR) in bladder of normal rats and investigate the distribution and safety of ¹²⁵I-UdR in rat bearing bladder cancer through pathology study. To search the pathological changes of the bladder cancer after the curatio of ¹²⁵I-UdR for the preparation of clinic application of ¹²⁵I-UdR by taking a further study about the pharmic safety and curative effect of ¹²⁵I-UdR in athymic mouse model bearing bladder cancer.Methods: (1) At different times after normal rats were given intravesical instillation ,rats were killed respectively, and radioactivity of various parts of organs were counted and taken for pathological examination. (2)A double-weekly dose of 2 mg N-methy1-N-nitrosourea (MNU) each time for 4 times intravesicular administration was given. The pathological dynamic changes of bladder mucosa were observed. (3) A relatively suitable therapeutic dose of intravesical administration of ¹²⁵I-UdR was 37.5MBq/kg in tumor-bearing rat blader. The injury circumstance of normal tissue from ¹²⁵I-UdR was analyzed.. The distribution of ¹²⁵I-UdR was estimated by SPECT scintigrams and analyzing the radioactivity of various organs determined byγscintillation counter after intravesical instillation of ¹²⁵I-UdR. The pharmic safety of tumor-bearing rat was evaluated by analyzing hemogram, biochemistry indexes and results of pathological examination. (4) The bladder cancer SCaBER cells were injected into the right flank skin of two small athymic mice. The volume of tumor will be 1cm3 ten days later. Taking the tumor out and cutting it into 1mm3 pieces. To transplant the tumor pieces to the back of 24 athymic mice which have been prepared after proper anaesthesia and backlying fixation. (5) A proper dosage (123.33MBq/kg) of ¹²⁵I-UdR was injected into the transplanted tumor of athymic mice...