- HENRY DRM'IKIUGUMUTEMBEI. "HM Mutembei, S Pesch, M Kowalewski, G Schuler, B Ugele,W Song and B Hoffmann 2006: Expression of Estrogen sulfotransferase in the testis of Immature and Mature boars.Reprod Dom Animal 41 (Suppl.1): 24.". In: Animal Reproduction Science 109 (2008) 319. Elsevier; 2006.
estrone sulfate (E1S) by far exceeding those of free estrone (E1). Expression of estrogen receptors has been observed in Leydig-, Sertoli- and germ cells. This suggests a paracrine and/or autocrine activity of the Leydig cell derived estrogens. In vitro studies with boar testicular tissue have demonstrated activity of both StS and EST. The bioavailability of free estrone might result from the interplay of both enzymes. We investigated for the localisation of EST enzyme in the testes of immature and mature boars by immunohistochemistry using samples from animals aged 50, 100, 150, 200 and 250 days. Rabbit polyclonal antibodies against human EST alongside negative controls with the rabbit serum were used. In all age groups both the EST was localised, with their signals restricted to the cytoplasm of the Leydig cells. The intensity of EST decreased as the boars matured. RT-PCR confirmed testicular expression of EST, in situ hybridisation confirmed localisation of EST in the Leydig cells. For a functional interpretation further studies are necessary. However, in respect to the lower activity of EST determined in the testis compared to the epididymis and the local circulatory system, rather the epididymis than the testis seems to be the origin of the high E1Sconcentrations determined in the testicular vein plasma.