Selenium complexes in the anterior pituitary of rats exposed to L-selenomethionine.
Selenium precipitates were demonstrated histochemically by silver amplification at light and electron microscopic levels in the anterior pituitary of rats exposed to L-selenomethionine (SeMeth). By electron microscopy (EM), the silver amplified selenium complexes were identified in somatotrophs, corticotrophs and gonadotrophs. Precipitates were observed mainly in the secretory granules and to a lesser extent in the lysosomes. The staining intensity increased with increasing amounts of SeMeth. Following a single injection of 3.7 mg Se/kg a substantial increase in staining was observed during the first 48 h after injection and precipitates could still be observed in the anterior pituitary after 2 weeks. During a long-term study where the rats were exposed to selenium contained in the drinking water (3.0 mg Se/l drinking water for 1, 2 or 4 weeks) an increasing amount of precipitates were observed during the first 2 weeks followed by a small decrease in staining intensity. Organic selenium, or rather a metabolite, is suggested to form bands with endogenous metal, primarily zinc, as has been suggested in the brain and anterior pituitary after exposure to sodium selenite.
Grønbaek
H
H
Department of Neurobiology, University of Aarhus, Denmark.
Thorlacius-Ussing
O
O
D000818:Animals; D011232:Chemical Precipitation; D006651:Histocytochemistry; D008297:Male; D008854:Microscopy, Electron; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D012643:Selenium / Q000378:metabolism*; D012645:Selenomethionine / Q000378:metabolism*
D012645:Selenomethionine; D012643:Selenium