Search

Pituitary adenylate cyclase activating polypeptide (PACAP) was first isolated from ovine hypothalamus and was known to stimulate the release of growth factor in various cells. Recently, we reported the cellular localization of PACAP and its type I (PAC1) receptor in rat placenta during pregnancy. Placenta is a critical organ that synthesizes several growth factors and angiogenic factors for the fetal development and its own growth. However, there is little information regarding the cellular localization of PACAP and its receptor in human placenta at various gestations. The aim of the present study was to define the expression and distribution of PACAP and PAC1 receptor mRNAs in the human placenta during the pregnancy period. PACAP and PAC1 receptor mRNAs were expressed in stroma cells of stem villi and terminal villi. At the early stage, on 7 and 14 weeks, PACAP and PAC1 receptor genes were moderately expressed in stroma cells surrounding the blood vessels within stem villi. These genes were strongly expressed in stroma cells of stem villi and terminal villi on 24 and 38 weeks. The expression of these genes was increased as gestation advanced, and localized in the same areas. Localization of PACAP and PAC1 receptor demonstrate the evidence that PACAP may play an important role, as an autoregulator or pararegulator via its PAC1 receptor. In conclusion, our findings strongly suggest that PACAP may have a critical role in physiological function of the placenta for gestational maintenance and fetal growth. [ABSTRACT FROM AUTHOR]

The placenta is an essential organ that synthesizes several growth and angiogenic factors for its own growth as well as fetal development. It is known that the placenta growth factor (PIGF) is a member of the vascular endothelial growth factor family and is critical for placental growth and fetal development. However, there is little information regarding the expression pattern and cellular localization of PIGF mRNA in rat placenta during pregnancy. The aim of this study was to define the distribution of PIGF mRNA in rat placenta at various gestations. RT-PCR analysis showed that the expression level of PIGF mRNA increased as gestation advanced. Using in situ hybridization histochemistry, positive cells of PIGF mRNA were detected in chorionic villi. PIGF mRNA was expressed in the trophoblast cells and stroma cells surrounding the blood vessels within chorionic villi on day 13 and 15. Also, positive signals of PIGF mRNA were strongly detected in stroma cells of chorionic villi on day 17, 19, and 21. In particular, the density and number of positive signals of PIGF mRNA was significantly increased as gestation advanced. The expression pattern of PIGF mRNA in rat placenta during pregnancy demonstrates that PIGF plays a functional role for placental growth and fetal development during mid-late pregnancy. [ABSTRACT FROM AUTHOR]