CONICET | Buscador de Institutos y Recursos Humanos

mPR receptors are expressed in the mouse spinal cord F. Labombarda1,2 , D. Meffre1, B. Delespierre1, S. Krivokapic-Blondiaux.1, S. L. Gonzalez2, A. F. De Nicola 2, M. Schumacher1, R. Guennoun1 (1) INSERM UMR788 and University Paris-Sud 11, Kremlin-Bicêtre, France (2) Instituto de Biologia y Medicina Experimental and Department of Human Biochemistry, University of Buenos Aires, Argentina. Progesterone (PROG) has different effects in spinal cord. The mechanisms by which progesterone exerts these effects may involve different receptors. Beside the nuclear progesterone receptor (PR), there are at least two potential membrane progesterone receptors that could account for progesterone actions. First, is the PROG binding protein referred to as PR membrane component-1 (PGRMC1) or 25-Dx. A second protein that could mediate PROG actions belongs to the three recently identified membrane PRs (mPR: mPRa, mPRb, or mPRg). In this study we investigated in mouse spinal cord the expression and distribution of this novel family of mPRs. RT-PCR analysis and sequencing of the amplified products demonstrated the expression of mPRa, mPRb and mPRg mRNA in spinal cord. Semi-quantitative RT-PCR showed no sex difference in mRNA expression of the three isoforms of mPR. In situ hybridization analysis showed the expression of mPRa and mPRb mRNA in motoneurons but could not detect mPRg mRNA. The analysis of mPRa expression and distribution at the protein level is under progress. Preliminary results showed that mPRa is expressed in both neurons and glial cells. Our results suggest that mPR receptors may be implicated in different biological effects of PROG described in the spinal cord. Acknowledgments: This work was partly supported by AFM (project: R06083LL, grant: RAE06031LLA) and a cooperative program between the Governments of France and Argentina (INSERM/CONICET)