Mating changes the subcellular distribution and the functionality of estrogen receptors in the rat oviduct.
BACKGROUND
Mating changes the mode of action of 17beta-estradiol (E2) to accelerate oviductal egg transport from a nongenomic to a genomic mode, although in both pathways estrogen receptors (ER) are required. This change was designated as intracellular path shifting (IPS).


METHODS
Herein, we examined the subcellular distribution of ESR1 and ESR2 (formerly known as ER-alpha and ER-beta) in oviductal epithelial cells of rats on day 1 of cycle (C1) or pregnancy (P1) using immunoelectron microscopy for ESR1 and ESR2. The effect of mating on intraoviductal ESR1 or ESR2 signaling was then explored comparing the expression of E2-target genes c-fos, brain creatine kinase (Ckb) and calbindin 9 kDa (s100g) in rats on C1 or P1 treated with selective agonists for ESR1 (PPT) or ESR2 (DPN). The effect of ER agonists on egg transport was also evaluated on C1 or P1 rats.


RESULTS
Receptor immunoreactivity was associated with the nucleus, cytoplasm and plasma membrane of the epithelial cells. Mating affected the subcellular distribution of both receptors as well as the response to E2. In C1 and P1 rats, PPT increased Ckb while both agonists increased c-fos. DPN increased Ckb and s100g only in C1 and P1 rats, respectively. PPT accelerated egg transport in both groups and DPN accelerated egg transport only in C1 rats.


CONCLUSIONS
Estrogen receptors present a subcellular distribution compatible with E2 genomic and nongenomic signaling in the oviductal epithelial cells of C1 and P1 although IPS occurs independently of changes in the distribution of ESR1 and ESR2 in the oviductal epithelial cells. Mating affected intraoviductal ER-signaling and induced loss of functional involvement of ESR2 on E2-induced accelerated egg transport. These findings reveal a profound influence on the ER signaling pathways exerted by mating in the oviduct.
Orihuela
Pedro A
PA
Laboratorio de Inmunología de la Reproducción, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile. pedro.orihuela@usach.cl
Zuñiga
Lidia M
LM
Rios
Mariana
M
Parada-Bustamante
Alexis
A
Sierralta
Walter D
WD
Velásquez
Luis A
LA
Croxatto
Horacio B
HB
D000818:Animals; D064026:Calbindins; D052276:Creatine Kinase, BB Form / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D030762:Estrous Cycle / Q000235:genetics / Q000378:metabolism; D005187:Fallopian Tubes / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D005260:Female; D036145:Ginsenosides / Q000494:pharmacology; D009570:Nitriles / Q000494:pharmacology; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D011247:Pregnancy; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011960:Receptors, Estrogen / Q000819:agonists / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D012502:Sapogenins / Q000494:pharmacology; D012726:Sexual Behavior, Animal / Q000502:physiology*; D014018:Tissue Distribution; D011422:Propionates
D064026:Calbindins; D052276:Creatine Kinase, BB Form; D036145:Ginsenosides; D009570:Nitriles; D016760:Proto-Oncogene Proteins c-fos; D011960:Receptors, Estrogen; D064030:S100 Calcium Binding Protein G; D012502:Sapogenins; C486182:2,3-bis(4-hydroxyphenyl)-propionitrile; D011422:Propionates; C576508:S100g protein, rat; C507965:ginsenoside 20S-protopanaxatriol