Glucocorticoid receptor in the rat epididymis: expression, cellular distribution and regulation by steroid hormones.
Glucocorticoids regulate several physiological functions, including reproduction, in mammals. Curiously, little is known about glucocorticoid-induced effects on the epididymis, an androgen-dependent tissue with vital role on sperm maturation. Here, RT-PCR, Western blot and immunohistochemical studies were performed to evaluate expression, cellular distribution and hormonal regulation of glucocorticoid receptor (GR) along rat epididymis. The rat orthologue of human GRalpha (mRNA and protein) was detected in caput, corpus and cauda epididymis and immunolocalized in the nucleus and cytoplasm of different epididymal cells (epithelial, smooth muscle and interstitial cells) and nerve fibers. Changes in plasma glucocorticoid and androgen levels differentially regulated GR expression in caput and cauda epididymis by homologous and heterologous mechanisms. In vivo treatment with dexamethasone significantly changed the expression of glucocorticoid-responsive genes and induced ligand-dependent GR nuclear translocation in epithelial cells from epididymis, indicating that GR is fully active in this tissue. Heterologous regulation of androgen receptor expression by glucocorticoids was also demonstrated in cauda epididymis. Our results demonstrate that the epididymis is under glucocorticoid regulation, opening new insights into the roles of this hormone in male fertility.
Silva
Erick J R
EJ
Section of Experimental Endocrinology, Department of Pharmacology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua 03 de maio 100, INFAR, Vila Clementino, São Paulo, SP 04044-020, Brazil.
Queiróz
Daniel B C
DB
Honda
Luciana
L
Avellar
Maria Christina W
MC
D000315:Adrenalectomy; D000367:Age Factors; D000728:Androgens / Q000097:blood; D000818:Animals; D004822:Epididymis / Q000187:drug effects* / Q000378:metabolism*; D005298:Fertility / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology; D012739:Gonadal Steroid Hormones / Q000097:blood / Q000494:pharmacology*; D008297:Male; D009919:Orchiectomy; D051381:Rats; D017208:Rats, Wistar; D011965:Receptors, Glucocorticoid / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D014018:Tissue Distribution / Q000187:drug effects
D000728:Androgens; D005938:Glucocorticoids; D012739:Gonadal Steroid Hormones; D011965:Receptors, Glucocorticoid