Analysis of the High Risk Factors of Endometrial Adenocarcinoma : Abnormal Excretion in Urinary Steroids in Androgen Sterilized Rats

: We experimentally produced spontaneous endometrial carcinoma in anovulatory sterilized Sprague-Dawley rats (ASR) after 500 days of age and compared the 24 hour urinary steroid excretion patterns in ASR with those in normal control rats (NR). The results obtained were as follows: The 24 hours urinary 17-ketosteroid, 11-deoxy-17-ketosteroid and 11-oxy-17-ketosteroid levels of 500-day-old ASR were 127.5 micrograms/day, 73.4 micrograms/day and 54.1 micrograms/day which were 1/3, 2/5 and 1/3 of the same aged NR, respectively. Although the 24 hour urinary androsterone, etiocholanolone and dehydroepiandrosterone of 100-day-old ASR were significantly higher than those of the same aged NR, the seven fractionated 17-ketosteroid levels of 500-day-old ASR were lower than those of NR. Moreover, the urinary androsterone, etiocholanolone and 11-ketoetiocholanolone of 500-day-old ASR were significantly lower than those of NR. The total excretion of tetrahydrocortisol, tetrahydrocortisone and tetrahydrocorticosterone of 100- and 500-day-old ASR were 318 micrograms/day and 244 micrograms/day which were slightly higher levels than those of NR. And the urinary tetrahydrocortisol level of ASR was found to be higher than that of NR. The present results suggested that an abnormality in androgen metabolism of ASR relative to NR was one of the high risk factors in endometrial carcinogenesis in ASR.