Establishment and comparison of two methods to produce a rat model of mammary gland hyperplasia with hyperprolactinemia

Abstract This study aimed to establish and compare models of mammary gland hyperplasia (MGH) with hyperprolactinemia (HPRL) using two different methods. The models provide information on the relationship between mammary gland hyperplasia and associated hormones. Model A was constructed using intramuscular injections of estradiol benzoate injection (EBI), followed by progesterone (P), and then metoclopramide dihydrochloride (MDI). Model B was designed by administering MDI, follow by EBI, and then P intramuscularly. Model B showed higher MGH progression compared with model A. Notably, increase in estradiol (E2) was negatively correlated with prolactin (PRL) secretion. However, PRL levels in model B were significantly higher compared with the levels in model A. Estrogen (ER), prolactin receptor (PRLR), and progesterone receptor (PR) mRNA and protein expression levels in model B rats were positively correlated with changes in the corresponding hormone levels. However, E2, P, and PRL levels in model A showed no direct relationship with levels of the mRNAs of related hormones and protein expression levels. Our results suggest that model B is an appropriate model of MGH with HPRL that can be used to perform further studies about the interactions of the E2, P, and PRL hormones in this disorder.

Comparative assessment of effect of malt with different bud length on prolactin in hyperprolactinemia rat

Malt is the mature fruit of Hordeum vulgare L. after germination and drying and has been applied for treatment female abnormal galactorrhea. Previous studies have showed total alkaloids in malt have anti-HPRL effect. However, total alkaloids of malt change with the growth cycle, and the specified levels of total alkaloids in different bud length of malt have not been decided. To determine the definitive level of total alkaloids in different buds of malt and the most suitable bud length for clinical application by comparing effects on hyperprolactinemia rat. During the budding of malt, the content of total alkaloids first increased and then decreased, and it peaked at a bud length of 0.75 cm. Treated the HPRL model rats with different buds of malt, the PRL level was decreased, the number of PRLpositive cells and the mRNA expression level in the pituitary were significantly declined, and the number of dopamine D1 and D2 receptors in the hypothalamus was increased. The above changes were most significant in 0.75 cm bud. These results suggest that in terms of the content of effective substance and the effects on HPRL model rats, a malt bud length of 0.75 cm is optimal for clinical application.