Histotopography of the radiopharmaceuticals 75Se-selenomethionine and 75Se-selenite in critical organs of adult and embryonic mice

Adult male and pregnant mice received 75Se-labelled methionine and selenite, resp. The critical organs and the embryos were examined histoautoradiographically at different time intervals as to the organ distribution of the radiopharmaceuticals. All organs revealed a heterogeneity of the 75Se distribution with an intensity being unequally organo-specific and depending on the type of the radiopharmaceutical. 75Se-selenomethionine was deposited mainly in functional areas of kidneys, liver, bone marrow and testes thus causing a long-term retention and an intensive irradiation of these organs. In the embryos 75Se-seleno-methionine was distributed unequally preferring liver, hematopoietic areas of the bone marrow and the lens