Yoshida H, Fukunishi R
Gan. 1981 Apr;72(2):315-7.
The development of mammary dysplasia (mastopathia cystica) induced by 7,12-dimethylbenz[a]anthracene (DMBA) in neonatally androgenized female rats was dependent on estrogens, and cystic-type mammary dysplasia developed in rats with a relative or absolute excess of estrogens. At 2 days of age, 137 female rats were neonatally androgenized by single subcutaneous injections of 1.25 mg testosterone propionate (TP). At 50 days of age, all rats were given 20 mg DMBA by gastric intubation. About one-half of the TP rats were ovariectomized at 78 days of age. Rats in test groups were given daily intramuscular injections of 10 micrograms 17 beta-estradiol (E) or 4 mg progesterone (P) for 228 days starting from 78 days after birth. In all TP rats, corpora lutea were absent in the ovaries. the incidence of mammary dysplasia in TP rats was 89.7%. Ovariectomy (OVEX) of TP rats induced a significant and marked decrease in the incidence of mammary dysplasia (3.7%). In TP rats with OVEX, a high incidence of mammary dysplasia was found in those given E (95.7%) but not in those given P (0%). The incidences of cystic-type mammary dysplasia in TP rats, TP rats with E, TP rats with OVEX and E and TP rats with P were 65.5, 86.7, 91.3 and 0%, respectively.
新生期经雄激素化的雌性大鼠中，7,12-二甲基苯并[a]蒽（DMBA）诱导的乳腺发育异常（囊性乳腺病）的发生依赖于雌激素，在雌激素相对或绝对过量的大鼠中会出现囊性乳腺发育异常。在2日龄时，137只雌性大鼠通过单次皮下注射1.25mg丙酸睾酮（TP）进行新生期雄激素化。在50日龄时，所有大鼠经胃管给予20mg DMBA。约一半的TP大鼠在78日龄时进行卵巢切除。从出生后78天开始，试验组大鼠每天肌肉注射10μg 17β-雌二醇（E）或4mg孕酮（P），持续228天。在所有TP大鼠中，卵巢中均无黄体。TP大鼠乳腺发育异常的发生率为89.7%。TP大鼠进行卵巢切除（OVEX）后，乳腺发育异常的发生率显著且明显降低（3.7%）。在进行OVEX的TP大鼠中，给予E的大鼠乳腺发育异常发生率较高（95.7%），而给予P的大鼠则未出现（0%）。TP大鼠、给予E的TP大鼠、进行OVEX并给予E的TP大鼠以及给予P的TP大鼠中囊性乳腺发育异常的发生率分别为65.5%、86.7%、91.3%和0%。
