The two primary objectives currently pursued are to elucidate the effects of follicle stimulating hormone (FSH) on the polyamine (PA) biochemistry of the Sertoli cell (SC) and to determine whether or not FSH receptors (FSHR) may be implicated in infertility of an autoallergic etiology utilizing the Granulosa cell (GC) as an experimental model. The 1st project focuses on 3 specific areas: 1) The role of FSH in the induction of ornithine decarboxylase activity and mRNA accumulation and its effects on PA biosynthesis in SC, 2) The role of transglutamination and the effects of transglutaminase (TGase) inhibition on SC function, 3) Characterization of a spermine binding site in SC. The effects of media constituents on ODC induction and PA biosynthesis as well as the effects of PA depletion (inhibition of ODC by difluoromethyl ornithine and spermine synthase by s-adenosyl-1,8-diamine-3-thiooctane) on these processes as well as steroidogenesis and the cellular processing of FSH by SC will be investigated. TGase activity in SC will be studied with regard to its induction by serum factors and its substrate specificity. The spermine binding site binding affinity, specificity and chemical properties will be determined. The presence of a spermine binding protein on SC suggests a possible mechanism for cell to cell communication within the tubule lumen or between testicular compartments. The working hypothesis of the 2nd project suggests that antibody inactivation of the FSHR and/or membrane associated entities results in gonadal failure. Inactivation may occur by 1) the FSHR becoming antigenic by virtue of its association with FSH which was involved in a primary antibody response (heterogenization) 2) a secondary response antibody is produced which recognized the first antibody which was formed to FSH (anti-idiotype formation). In the latter case, antibodies directed against the paratope of the anti-FSH antibodies would interact directly with the FSH binding region of R. In order to directly test the hypothesis, the effect of active immunization with purified antibody to FSH will be studied. Antisera with a positive titer for anti-idiotype will be tested for the presence of anti-R antibodies. It will be necessary to initially characterize the FSHR in GC and to prepare an isotopically labeled FSHR for later use in immunodiagnostic studies. The long term goals are to establish which specific biochemical processes are essential to FSHR function and modulation of FSH mediated cellular activation and to determine whether or not FSHR may be implicated in infertility of an auto-allergic etiology.
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