Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)




Historically the interest in organic derivatives of selenium has been primarily centered on selenium analogs of sulfur compounds, the selenium analogs of the sulfur-containing amino acids. Experimental studies of the metabo1ism of seleno-organic compounds have been limited to a large extent by their unavailability. Dimethyl selenide is the only organic selenium compound that has been identified as an exhalation product from a laboratory animal injected with an inorganic form of· selenium. Although the toxicity of selenium has been known for many years, the mode of action of the element has remained a mystery. Many investigations on the toxicity of selenium have been concerned only with selenium analysis of the excreta of livestock and/or laboratory animals in an attempt to establish a detoxification pathway for selenium. Isolation and identification of excreted selenium compounds, with the exception of selenite or selenite, have been extremely difficult. A recently identified seleno-organic compound, isolated from rat urine after oral and intraperitoneal administration of subtoxic levels of selenite, gave occasion for this study. The compound identified as a trimethylselenonium moiety was studied in the chloride formb. This study was originally undertaken to help clarify the pathway of selenium detoxification in the rat by investigating the metabolism of the newly identified excretory product (TMSe moiety). A complete metabolic investigation of a selenium compound should answer the following questions: (1) Is the compound metabolized to a volatile product, at what rate is this volatile product excreted from the lungs, and what percentage of the administered dose is eliminated in this way? (2) Is it or one of its metabolic products excreted in the urine, at what rate is the selenium excreted, am what percentage of the administered dose is excreted in the urine? (3) Is it or a metabolized product present in the feces and what percentage of the administered dose is eliminated in this way? (4) Is selenium retained in the animal, to what degree, and what is the distribution of the retained selenium in the ·animal? (5) Is the compound itself toxic? If so, at what selenium concentration. During the study of questions- one and two above- it was discovered that the compound (or a metabolized product of it) was itself toxic--although at quite high selenium concentrations—and further work was then done to answer question number five.

Library of Congress Subject Headings

Selenium--Physiological effects.



Number of Pages



South Dakota State University