O-36: The Role of Galectin-3 in Rat CorpusLuteum Maintenance

Background: Galectin, an animal lectin that recognizes b-galactosides of glycoconjugates, is involved in multiple biological functions such as cell growth, differentiation, apoptosis, signal transduction and angiogenesis. Overexpression of galectin-3 was observed in different tumors which was related to pro-angiogenic activity. In addition, galectin-3 is intensely expressed in corpus luteum (CL) which was proposed to be associated with CL remodeling but the exact mechanism by which it works is not yet clear. Since angiogenesis play an important role in CL remaining or demise, here we sought to determine the role of galectin-3 in CL angiogenesis by using modified citrus pectin (MCP/Pectasol) as a known component to inhibit pro-angiogenic properties of galectine-3. Materials and Methods: Immature female Wistar rats weighting between 40-50g were stimulated with intraperitoneal injection of PMSG (10IU) (n=4). After 48h, anesthesia was performed three hours prior to intraperitoneal hCG injection and ovarian intrabursal injection of one ovary per animal was performed with a total volume of 50 ul containing 0.5 mg/ml MCP dissolved in phosphate buffer solution (PBS). Contralateral ovary was injected with equal volume of PBS and used as control. Ovaries were removed 48 hours post hCG stimulation, paraffin embedded and sectioned (5 um). The total number of CL (healthy + apoptotic) was counted in MCPtreated and control ovaries every twenty section and results were expressed as Mean ± SEM. Endothelial celldensity in CL was assessed by immunohistochemistry analysis using goat monoclonal anti-PECAM/CD31 antibody. The intensity of immunostaining was quantified by using a software using C language (Microsoft Visual Studio 2005 and Dot Net framework 2.0). Statistical analysis was performed by using SPSS version 16. Results: The number of CL in regression was higher in MCP-treated (11.0 ± 0.68) compared to control (9.8 ± 0.62) ovaries, which was not reach significance. We found a significant decreased endothelial cell density in CL of MCP-treated ovary compared to CL of control ovary as revealed by decreased PECAM immunostaining (p