Temporal relationships among uterine pituitary adenylate cyclase-activating polypeptide, decidual prolactin-related protein and progesterone receptor mRNAs expressions during decidualization and gestation in rats

摘要

Pituitary adenylate cyclase-activating peptide (P ACAP), a novel compound with vasoactive intestinal polypeptide-like activity, was recently shown to be localized in the neuronal endings of the human uterus. The purpose of the present study was to assess the functional presence of P ACAP mRNA in the decidual endometrium and its relationship to the expression levels of decidual prolactin-related protein (dPRP) and the progesterone receptor mRNAs during decidual- ization and pregnancy in Sprague-Dawley rats. PACAP was constitutively and temporally expressed in the decidual endometrium and gravid uterus. The time-dependent correlated expression levels of P ACAP , dPRP and the proges- terone receptor were induced by the neurogenic reproductive signals, i.e. the vagino-cervical/deciduogenic stimuli of decidualization and by the normal equivalent stimuli of mating/blastocyst implantation of gestation. Correlation among the mRNA expression levels of P ACAP , dPRP and the progesterone receptor and the coordinated inhibitory actions of the anti-progesterone (RU-486) suggest that there is also correlated time-dependent steroid regulation of the mRNA levels of P ACAP , dPRP and the progesterone receptor in the decidual and pregnant uteri. One possible functional meaning for the time-related localization of endometrial/uterine P ACAP could be to facilitate endometrial blood flow and increase the availability of metabolic substrates to the developing deciduoma or embryo. The study demonstrates the potential importance of P ACAP expression in the regulation of the maternal feto-placental component and suggests a prominent reproductive role for the neuropeptide in mammalian pregnancy.