Investigation of the male predominance of bladder cancer

To analyze the participation of male hormone in the genesis of urinary bladder carcinoma. Weadministered gonadotropin-releasing hormone analogue (RH analogue) to the experimental model ofmale rats where carcinoma is induced by N-butyl-N-(4 hydroxybutyl)nitrosamine (BBN),and furtherexamined the relation between the change of male hormone kinetics and the genesis ratio.Experiment1:the changes of male rat pituitary-testicular axis induced by a LH RH analogue were examined. Serumlh,FSH and testosterone levels showed their peaks one day after the LH RH analogue depot （1mg /body）weight,testo-sterone became castration level one week afterthe LH RH analogue injection. BBN did not influence pituitary-testicular axis and action of theLH RH analogue.Experiment 2: We divided 143 male Wistar rats of 9 weeks into 5 groups. Group 1：0.05% BBN had been administered for 8 weeks. Group 2：0.05% BBN and LH RH analogue for 8 weeks. Group 3：0.05% BBN for 8 weeks and then LH RH analogue for 16 weeks. Group 4：0.05% BBN for 8 weeks and at the same time LH RH analogue for the overall process. Group 5：0.05% BBN for 8 weeks after carrying out orchidectomy. Cystectomy was conducted on all of the rats24 weeks after the experiment had started so as to examine histologically.diminution of testosteroneinhibited rat bladder carcinogenesis induced by BBN. The way of castration，LH RH analogue depot, LH RH analogue depot, LH RH analogue depot可能在一个不同的方式来包括bladder carcinogenesis.关于phenomenon mayindicate the regulatory system in the hyperamus -pituitary-testicular axis on the bladdercarcinogenesis. The inhibition was most significant when LH RH analogue was administered in Thepromotion phase of bladder carcinogenesis.Further studies are required to make clear the augmentedinhibition of LH RH analogue on bladder carcinogenesis。

To analyze the participation of male hormone in the genesis of urinary bladder carcinoma. We administered gonadotropin-releasing hormone analogue (LH・RH analogue) to the experimental model of male rats where carcinoma is induced by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN),and further examined the relation between the change of male hormone kinetics and the genesis ratio.Experiment 1: the changes of male rat pituitary-testicular axis induced by a LH・RH analogue were examined. Serum LH, FSH and testosterone levels showed their peaks one day after the LH・RH analogue depot (1 mg/body weight, monthly) injection and decreased afterwards. testo-sterone became castration level one week after the LH・RH analogue injection. BBN did not influence pituitary-testicular axis and action of the LH・RH analogue.Experiment 2: We divided 143 male Wistar rats of 9 weeks into 5 groups. Group 1: 0.05% BBN had been administered for 8 weeks. Group 2: 0.05% BBN and LH・RH analogue for 8 weeks. Group 3: 0.05% BBN for 8 weeks and then LH・RH analogue for 16 weeks. Group 4: 0.05% BBN for 8 weeks and at the same time LH・RH analogue for the overall process. Group 5: 0.05% BBN for 8 weeks after carrying out orchidectomy. Cystectomy was conducted on all of the rats 24 weeks after the experiment had started so as to examine histologically.Diminution of testosterone inhibited rat bladder carcinogenesis induced by BBN. The way of castration, surgical castration or medical castration by LH・RH analogue depot, might act in a different way to inhibit the bladder carcinogenesis. The above phenomenon may indicate the regulatory system in the hypothalamus-pituitary-testicular axis on the bladder carcinogenesis. The inhibition was most significant when LH・RH analogue was administered in the promotion phase of bladder carcinogenesis.Further studies are required to make clear the augmented inhibition of LH・RH analogue on bladder carcinogenesis.