Cervical changes in estrogen receptor alpha, oxytocin receptor, LH receptor, and cyclooxygenase-2 depending on the histologic compartment, longitudinal axis, and day of the ovine estrous cycle

• Published in: Theriogenology 2014-04, Vol.81 (6), p.813-824
• Main Authors: Rodríguez-Piñón, M., Gonzalez, R., Tasende, C., Bielli, A., Genovese, P., Garófalo, E.G.
• Format: Article
• Language: English
• Subjects: Animals; Cervix; Cervix Uteri - metabolism; Cyclooxygenase 2 - metabolism; Cyclooxygenase-2; Estrogen Receptor alpha - metabolism; Estrous cycle; Estrous Cycle - metabolism; Ewe; Female; Hormone receptor; Receptors, LH - metabolism; Reproduction; Sheep - physiology; Time Factors
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2013.12.019

The aim was to investigate the histologic distribution of estrogen receptor α (ERα), oxytocin receptor (OxR), LH receptor (LHR), and cyclooxygenase-2 (COX-2) in the cervix of the ewe during the estrous cycle. Immunohistochemistry was performed in the cranial and caudal cervix of Corriedale ewes on Day 1 (n = 6), 6 (n = 5), or 13 (n = 6) after estrous detection (Day 0). The ERα proportional score (%ERα nuclei) was lower in the cranial cervix than in the caudal cervix, whereas the OxR and COX-2 immunostaining areas (%areas) were greater in the cranial cervix than in the caudal cervix (P < 0.04). The %ERα nuclei decreased from Days 1 to 13 in luminal epithelia, but increased from Days 1 to 6 or remained unchanged in stromata (P < 0.003). The %OxR area was higher on Day 6 than on Days 1 and 13 in the superficial glandular epithelium, and increased from Days 1 to 13 in the deep glandular epithelium (P < 0.04). The %LHR area increased during the estrous cycle in luminal epithelia and fold stroma (P < 0.004). The %COX-2 area was restricted to epithelia, and it was lower on Day 1 than on Days 6 and 13 in luminal epithelia (P < 0.05). Differences in ERα, OxR, LHR, and COX-2 between cranial and caudal cervical zones indicate different physiological functions, and their cyclic variations in the cervical epithelia, in contrast to little or no variations in the stroma, suggest a hormone-responsive driving role of epithelia in cervical function.