QUANTIFICATION OF INSULIN-LIKE-GROWTH-FACTOR-I RECEPTORS ON GRANULOSA-CELLS WITH FLOW-CYTOMETRY AFTER FOLLICULAR STIMULATION

The presence of insulin-like growth factor I (IGF-I) receptors on gran ulosa cells was investigated by flow cytometric analysis. Granulosa ce lls were retrieved from follicular fluid after oocyte retrieval during assisted reproduction technology procedures. Whole samples of follicu lar fluid were pooled and the cellular fraction analysed. In order to analyse granulosa cells only we developed a dual labelling technique w hereby granulosa cells were identified as CD45 negative cells, disting uishing them from leukocytes which are CD45 positive. Analysis of the IGF-I receptor was done by staining the sample with a monoclonal anti- IGF-I receptor antibody (alpha IR3 clone) and goat anti-mouse phycoery thrin labelled antibody. After identification of the presence of IGF-I receptors, receptor expression was quantified by calibration of the f luorescence signals. We analysed 10 patients' samples and showed 559-1 774 binding sites per granulosa cell with a mean value of 1125 +/- 382 (SD).