Abstract
Sections of human adult testicles and of testicles from dog, rabbit, guinea pig, rat and mouse as well as of two seminomas were stained for nonspecific alkaline phosphatase and for 5-nucleotidase. The most outstanding feature in the testicles of all species examined is the presence of 5-nucleotidase predominantly located in the nuclei of the spermatogenic elements. In the two seminomas 5-nucleotidase was likewise found in the nuclei of the tumor cells. The validity of these findings is discussed and it is concluded that the predominantly nuclear localization reflects the true distribution of 5-nucleotidase in these cells.
The seminomas are not only rich in 5-nucleotidase, but contain apparently considerably larger amounts of nonspecific alkaline phosphatase than do normal human spermatogenic cells. The seminomas, therefore, show a distinct staining pattern as regards 5-nucleotidase and alkaline phosphatase so far apparently not observed in other tumors.