With aging of the male SAM mouse, the content of testosterone (T) would decrease while the content of estradiol (E2) would not change very much, so the ratio of E2/T would increase.

• 雄性SAM鼠随着年龄的增长，血清睾酮（T）含量下降，雌二醇（E2)含量无明显变化，E2/T比值升高。