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Title: Urinary trimethylselenonium ion (TMSe) as an index of selenium (Se) exposure in rats

Conference · · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)
OSTI ID:5320822

Large doses of certain Se compounds have been suggested as cancer chemoprevention agents in humans and better techniques for assessing Se status at such intakes are needed. Others have shown that urinary TMSe excretion is a function of Se exposure in rats and an HPLC method has recently been developed for measuring TMSe in urine. In their studies, young male rats were injected i.p. with 6 to 600 ..mu..g Se as selenite or L-selenomethionine containing 3..mu..Ci /sup 75/Se as the appropriate tracer. Urine was collected for 24 hours and desalted. TMSe was separated by HPLC on a strong cation exchanger with NH/sub 4/C/sub 2/H/sub 3/O/sub 2/ (pH 5.0) as the eluting buffer. Identification of TMSe was confirmed by autoradiographic TLC vs. authentic standards. The fraction of urinary Se excreted as TMSe increased from 2 to 70% as the amount of selenite injected increased. Only 3 to 53% appeared in urine as TMSe after injection of equivalent doses of selenomethionine. There was little or no effect of crude (chow) vs. purified (casein) diet on the excretion of TMSe after selenite injection, but Se-deficient rats excreted more Se in the form of TMSe than Se-supplemented rats. Urinary TMSe is a promising tool for assessing Se exposure but more work is needed to evaluate the effect of various dietary forms of Se on the excretion of TMSe in the urine.

Research Organization:
Dept. of Agriculture, Beltsville, MD
OSTI ID:
5320822
Report Number(s):
CONF-8604222-; TRN: 86-028431
Journal Information:
Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
Country of Publication:
United States
Language:
English