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Endometrial Oxytocin Receptor Concentration and Activity in Prepubertal Ewe Lambs
Author(s) -
Lamming GE,
Hunter M,
Scholey DV,
Mann GE
Publication year - 2005
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/j.1439-0531.2005.00565.x
Subject(s) - oxytocin , oxytocin receptor , endocrinology , medicine , receptor , prostaglandin , population , prostaglandin f , biology , environmental health
Contents We have measured endometrial oxytocin receptor concentrations during prepuberty in ewe lambs, and have investigated the effect of progesterone on the activity of these receptors. In the first study, oxytocin receptor concentrations were undetectable in 2‐week prenatal lambs but had increased immediately following birth and were then maintained throughout prepubertal life. Despite the presence of oxytocin receptors animals showed no prostaglandin F 2 α (PGF 2 α ) release in response to exogenous oxytocin challenge at either 3 or 5 months of age. In a second study in 4‐month‐old ewe lambs treatment with exogenous progesterone resulted in the appearance of PGF 2 α release in response to oxytocin after 10 days of treatment. Thus, during the prepubertal life, ewe lambs possess the prerequisites of a luteolytic mechanism in that they have a dormant population of oxytocin receptors in which progesterone can induce oxytocin‐stimulated PGF 2 α release.