Biomaterial Database

Regulation of sex differences in progesterone receptor expression in the medial preoptic nucleus of postnatal rats. 2002

P S Quadros, and A Y N Goldstein, and G J De Vries, and C K Wagner

Center for Neuroendocrine Studies and Neuroscience and Behaviour Program, University of Massachusetts, Amherst, MA, USA.

The medial preoptic nucleus (MPN) of the rat, an excellent model for understanding the mechanisms involved in sexual differentiation, is highly sensitive to gonadal hormones during both pre- and post-natal life. Progesterone receptor (PR) expression is sexually dimorphic in the prenatal MPN. Males have significantly higher levels of PR-immunoreactivity (PRir) than females from approximately embryonic day 19 through at least the day of birth, suggesting that PR may play a role in sexual differentiation. Because the MPN is still sensitive to steroid hormones postnatally, the present study investigated PR expression in the MPN of males and females after birth using immunocytochemistry. Results indicate that a sex difference in PR expression persists until at least postnatal day (P) 28. However, females begin to express PR around P10. Because oestradiol regulates PR expression in the adult brain, this study also examined the influence of gonadal hormones on PR expression in the neonatal male and female MPN. Castration on the day of birth significantly reduced levels of PRir in the MPN by 24 h following surgery. Ovariectomy on P4, before the onset of ovarian steroidogenesis, prevented the induction of PR expression in the female MPN, observed in controls by P13. In both sexes, the presence of PRir in the MPN is dependent on gonadal hormone exposure. These findings suggest that differences in steroid secretion by the neonatal male and female gonads are responsible for producing sex differences in the level of PR expression in the postnatal MPN.

UI	MeSH Term	Description	Entries
D007150	Immunohistochemistry	Histochemical localization of immunoreactive substances using labeled antibodies as reagents.	Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D008297	Male		Males
D009919	Orchiectomy	The surgical removal of one or both testicles.	Castration, Male,Orchidectomy,Castrations, Male,Male Castration,Male Castrations,Orchidectomies,Orchiectomies
D010052	Ovariectomy	The surgical removal of one or both ovaries.	Castration, Female,Oophorectomy,Bilateral Ovariectomy,Bilateral Ovariectomies,Castrations, Female,Female Castration,Female Castrations,Oophorectomies,Ovariectomies,Ovariectomies, Bilateral,Ovariectomy, Bilateral
D010053	Ovary	The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.	Ovaries
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011301	Preoptic Area	Region of hypothalamus between the ANTERIOR COMMISSURE and OPTIC CHIASM.	Area Preoptica,Lateral Preoptic Area,Medial Preoptic Area,Preoptic Nuclei,Area Preopticas,Area, Lateral Preoptic,Area, Medial Preoptic,Area, Preoptic,Areas, Lateral Preoptic,Areas, Medial Preoptic,Areas, Preoptic,Lateral Preoptic Areas,Medial Preoptic Areas,Nuclei, Preoptic,Nucleus, Preoptic,Preoptic Area, Lateral,Preoptic Area, Medial,Preoptic Areas,Preoptic Areas, Lateral,Preoptic Areas, Medial,Preoptic Nucleus,Preoptica, Area,Preopticas, Area
D011980	Receptors, Progesterone	Specific proteins found in or on cells of progesterone target tissues that specifically combine with progesterone. The cytosol progesterone-receptor complex then associates with the nucleic acids to initiate protein synthesis. There are two kinds of progesterone receptors, A and B. Both are induced by estrogen and have short half-lives.	Progesterone Receptors,Progestin Receptor,Progestin Receptors,Receptor, Progesterone,Receptors, Progestin,Progesterone Receptor,Receptor, Progestin
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia