title: Chemical forms of selenium in rat tissues after administration of selenite or selenomethionine.
abstract: The chemical forms of selenium (Se) were determined in erythrocyte and liver proteins after injection of 75Se as either sodium selenite or selenomethionine (Se-Met) in male weanling rats. Gel-filtration chromatography (Sephadex G-150) of erythrocyte lysate revealed labeling of four fractions corresponding to void volume proteins, glutathione peroxidase (GPx), hemoglobin (Hb) and low-molecular-weight materials. Acid hydrolysates of erythrocyte protein fractions and whole liver were analyzed by ion-exchange chromatography (Dionex DC6A). Void volume proteins contained principally selenocysteine (75Se-Cys) in [75Se]selenite-injected animals. This material contained both 75Se-Met and 75Se-Cys 1 d postinjection in 75Se-Met-injected animals, but primarily 75Se-Cys at 20 d afterwards. GPx contained 75Se as 75Se-Cys regardless of the selenium compound injected. Hb of 75Se-Met-injected animals contained principally 75Se-Met at both 1 and 20 d postinjection. In [75Se]selenite-injected animals, 75Se was present in hemoglobin as two unidentified forms. In acid hydrolysates of whole liver 75Se was recovered principally as 75Se-Cys from animals injected with [75Se]selenite. For animals injected with 75Se-Met, liver 75Se was present initially as 75Se-Met, but after 5 d the majority of liver 75Se was as Se-Cys. No differences were found in deposition of 75Se in liver, kidney, testes, erythrocytes or plasma in rats injected with labeled selenite or Se-Met, but a significantly greater retention was found in muscle of Se-Met-injected rats as compared to those given selenite.
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D003545:Cysteine / Q000031:analogs & derivatives / Q000378:metabolism; D004910:Erythrocyte Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D011868:Radioisotopes; D051381:Rats; D020887:Selenious Acid; D012643:Selenium / Q000378:metabolism*; D017279:Selenocysteine; D012645:Selenomethionine / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D006454:Hemoglobins; D011868:Radioisotopes; D017279:Selenocysteine; D012645:Selenomethionine; D005979:Glutathione Peroxidase; D020887:Selenious Acid; D012643:Selenium; D003545:Cysteine