Submission Number: CHR-4-4-6
Abstract Number: 413
EXPRESSION OF ANGIOPOIETINS IN THE HUMAN CORPUS LUTEUM OF THE MENSTRUAL CYCLE AND SIMULATED EARLY PREGNANCY.
C Wulff 1, WC Duncan* 2, DG Armstrong 3 and HM Fraser 1
MRC Human Reproductive Sciences Unit, Edinburgh, UK 1
Department of Obstetrics and Gynecology, Edinburgh, UK 2
Roslin Institute, Roslin, UK 3
In the human corpus luteum (CL) extensive angiogenesis accompanies luteinization, and the process is physiologically important for CL function. During luteolysis, the endothelial cells die, while in a conceptual cycle, the CL persists both functionally and structurally. The Angiopoietins-1 (Ang-1) and -2 (Ang-2) are a novel family of vascular regulators which may be involved in controlling these diverse changes in the microvasulature. The purpose of the present study was to localize and quantify by in situ hybridization Ang-1 and Ang-2 mRNA expression in the human CL throughout its functional life span (i.e. early, mid- and late luteal phase, n=6 per group) and after exposure to exogenous hCG (n=3) to 'rescue' the CL. In situ hybridization was performed in fixed tissue with radio labeled riboprobes for Ang-1 and Ang-2, respectively. After autoradiographic exposure, grain concentrations were quantified by image analysis. Ang-1 mRNA was expressed uniformly at a low level in the CL and the stroma of all groups. Highest grain density (p<0.05) was found during early luteal phase. In contrast, Ang-2 mRNA was highly expressed in a minority of granulosa and theca luteal cells and to a lesser degree in a number of endothelial cells. In the stroma, expression of Ang-2 was only present in endothelial cells. Highest Ang-2 mRNA grain concentration (p<0.05) was detected in the rescued CL. These results show that Ang-1 and Ang-2 are localized differentially in the human CL and suggest that Ang-1 is up regulated during early luteal phase, whereas Ang-2 is increased during luteal rescue. .
Keywords: Corpus luteum, Angiogenesis, Angiopoietins
This abstract is being presented at: 2:00 PM in session:
SESSION 14: CORPUS LUTEUM II