Quinestrol

Infertility control with EP-1 (quinestrol: levonorgestrel = 1:2) has proven effective in a variety of rodents. Previous studies have focused on the effects of EP-1 in terms of sterility; however, little is known about its cross-generational impact. In this study, the emotional and social behavior, gonadal metabolomics, serum hormone levels, and related brain receptors in adult offspring were examined following exposure to EP-1 (3 or 5 mg/kg), which was administered to dams 3 and 10 days postnatally by gavage. The results showed that EP-1 exposure enhanced anxiety-like behavior in males and diminished social behavior in both females and males. EP-1 exposure reduced the levels of l-glutamine and l-glutamic acid in the ovaries and those of l-glutamine, L‑serine, and l-phenylalanine in the testes, possibly resulting in metabolic abnormality and decreased estradiol and testosterone levels in serum. Furthermore, EP-1 exposure increased the expression of dopamine 1 receptor (D1R) in the nucleus accumbens (NAc), estrogen receptor α (ERα) and oxytocin receptor (OTR) in the medial preoptic area (MPOA), and that of ERα in the ventrolateral region of ventromedial hypothalami of females; contrastingly, it decreased the expression of vesicular GABA transporter in the medial amygdala while increasing that of D1R in the NAc and that of ERα and OTR in the MPOA of individual males. In conclusion, EP-1 exposure during lactation enhanced anxiety-like behavior in males, reduced sociality, affected gonadal function, reduced sex hormone levels, and altered the relative expression of receptors in the brain regions that regulate social behaviors in all offspring mice.

There have been some immunoassays reported for screening of the residues of estrogens in milk, but these methods can only determine one drug because of the limited recognition abilities of the used antibodies. Due to the broad specific recognition ability, receptor can be used as "special antibody" to develop pseudo immunoassay. However, there has been no article reporting the use of estrogen receptor for determination of estrogens in foods of animal origin so far. Furthermore, the recognition mechanism of estrogen receptor for estrogens have not been thoroughly studied.

In this study, a type of magnetic probe based on 17β-estradiol was synthesized that was used to produce the natural porcine estrogen receptor with ovarian as the source tissue. Then its recognition mechanisms for 13 estrogens were studied based on the optimal homological model. Results showed it only interacted with estrogens but did not interact with other steroid hormones. Then it was utilized as a broad specific recognition reagent to develop a direct competitive method on 96-well microplate for detection of the 13 drugs in milk. Due to the utilization of streptavidin-biotin labeled horseradish peroxidase as signal amplification system, the sensitivities for the 13 estrogens (limits of detection 0.007-0.0573 ng/mL) were improved for 33-100 folds in comparison with the use of conventional horseradish peroxidase system (limits of detection 0.31-3.53 ng/mL). This method showed no cross-reactivity with other steroid hormones, consistent with the docking result.

This is the first study reporting the use of magnetic probe to produce natural receptor from animal tissues, and this is also the first study reporting a natural estrogen-receptor-based method for multi-determination of estrogens in food sample. With the guidance of this study, more receptors and related analytical methods for other drugs or small molecules maybe are reported in the future.