Review Article
Efficacy of Female Rat Models in Translational Cardiovascular Aging Research
Table 1
Stages of ovarian aging in a female rat as described by Lu et al. (1979) [
24].
| Age (months) | Stages of ovarian aging in female rats |
| 5 months | Reproductive maturity | (i) Estrous cycle (4-5 days) | (ii) Elevated and constant levels of estradiol | (iii) Low levels of progesterone | (iv) Lack of hormone surges and ovulation |
| 6–8 months | Ovarian decline | (i) Decreased levels of estradiol and progesterone | (ii) Little or no follicles |
| 10–12 months | Irregularity of estrous cycles |
| 19 months | Constant estrous cycle | (i) Low to medium levels of serum estradiol, estrone, testosterone, androstenedione, and progesterone | (ii) Very low levels of 20α-hydroxyprogesterone | (iii) No preovulatory release of gonadotropin and prolactin | (iv) Increased levels of FSH |
| 24 months | Prolactin | (i) Increased levels of prolactin (abolished by ovariectomy) | (ii) Retained ability to develop follicles and corpora | (iii) Retained ability to secrete steroid hormones |
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