Role of Steroid Sulfonation as a Mechanism Controlling the Flow of Substrates through the Cascade of Steroidogenic Enzymes in the Porcine Testis

• Applicant: Professor Dr. Gerhard Schuler
• Subject Area: Animal Breeding, Animal Nutrition, Animal Husbandry
• Term: from 2010 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 152381467

Whereas in males of many mammalian species estrogens circulate in peripheral blood predominantly as free forms at low concentrations, in the boar large quantities of free and conjugated estrogens (with estrone sulfate being the predominant estrogen) occur in peripheral blood. In the porcine testicular-epididymal compartment estrogen receptors, steroid sulfatase (StS), estrogen sulfotransferase, aromatase and at least one putative steroid sulfate transporter (SOAT) are expressed in close proximity with each other, pointing to the synthesis, hydrolysis and transport of sulfated estrogens as local controlling elements of estrogenic actions in addition to de novo synthesis of free estrogens. The final goal of this project is to study in vivo the effect of StS inhibition on gonadal steroidogenesis and spermatogenesis in boars. Thus the aims of the first period of the project are 1) to close still existing gaps in the knowledge on the expression patterns of StS and the estrogen specific sulfotransferase SULT1E1 in the porcine testicular-epididymal compartment 2) to analyze the cellular localizations of SOAT and other putative steroid sulfate carriers such as OSCP1 in the testicular– epididymal compartment of the boar in relation to age, steroidogenesis and spermatogenesis and 3) to identify an effective StS inhibitor for the intended in vivo application in the boar.

• DFG Programme: Research Units
• Subproject of: FOR 1369: Sulfated Steroids in Reproduction