Biological availability of selenosugars in rats.

The biological availability and metabolism of two selenosugars orally administered to rats were investigated. Two other selenium species, selenite and trimethylselenonium ion (TMSe) were included in the study as positive and negative controls, respectively. Male Wistar strain rats (three per group) at 8 weeks of age were exposed to sodium selenite, TMSe, selenosugar 1 (methyl-2-acetamido-2-deoxy-1-seleno-beta-D-galactopyranoside) or selenosugar 2 (methyl-2-acetamido-2-deoxy-1-seleno-beta-D-glucopyranoside) through drinking water for 48 h.

Selenium metabolites in urine of cancer patients receiving L-selenomethionine at high doses.

We investigated, with quantitative HPLC/mass spectrometry, the selenium metabolites in urine from five cancer patients receiving high doses of L-selenomethionine over an extended period (2 x 4000 microg Se/day for 7 days, then 4000 microg Se/day for 21 days) as an adjunct to their normal cancer chemotherapy. Urine samples were collected at day 0 (all 5 patients), and at 2-3 additional collection times ranging from 1 to 33 days. The background selenium concentrations ranged from 12 to 55 microg Se/L and increased to 870 to 4420 microg Se/L for the five patients during the study.

Consequences of vapor enhancement on selenium speciation analysis by HPLC/ICPMS.

Recent work has shown the presence of volatile selenium metabolites in human urine and suggested that these compounds could compromise quantitative selenium analyses by ICPMS. We show that with a commonly used sample introduction system (pneumatic nebulizer and spray chamber), two volatile selenium species recently identified in urine, namely, dimethyl selenide and dimethyl diselenide, gave greatly increased ICPMS responses (up to 58-fold) relative to selenite, an effect related to their volatilization in the spray chamber resulting in enhanced transport to the plasma. The quantitative consequences of this effect were demonstrated by measurement of total selenium and selenium species in certified reference material, NIES CRM 18 human urine.

Marked individual variability in the levels of trimethylselenonium ion in human urine determined by HPLC/ICPMS and HPLC/vapor generation/ICPMS.

Selenium species were determined using HPLC/ICPMS and HPLC/vapor generation/ICPMS in the urine from seven human volunteers investigated at background selenium concentrations and at slightly elevated concentrations after ingestion of 200 microg Se as a selenite supplement. Trimethylselenonium ion (TMSe) was present, together with selenosugars, in the urine samples, a result that dispels recent doubts about its possible previous misidentification with a cationic selenosugar. Although TMSe was present as only a trace metabolite in urine from five of the seven volunteers (0.

Simultaneous administration of sodium selenite and mercuric chloride decreases efficacy of DMSA and DMPS in mercury elimination in rats.

Two chelating agents meso-2,3-dimercaptosuccinic acid (DMSA) and sodium 2,3-dimercapto-propane-1-sulphonate (DMPS) were tested for their efficiency in mercury removal from the body of rats in the presence and in the absence of selenium. Female Wistar rats were given a single intraperitoneal injection of mercuric chloride or an equimolar mixture of mercuric chloride and sodium selenite (1.5 micromol/kg body weight).

Endotoxin measurement in house dust using the end-point Limulus amoebocyte lysate method.

Endotoxin is a lipopolysaccharide, a part of gram-negative bacteria cell membrane commonly present in general and many occupational environments. This paper describes sample preparation and endotoxin measurement in 16 samples of house dust from urban homes (Zagreb, Croatia) using end-point chromogenic Limulus amoebocyte lysate (LAL) bioassay. House dust was collected on cellulose filters by vacuuming bedroom and living room floors, and was kept frozen until assayed.

Succimer treatment and calcium supplementation reduce tissue lead in suckling rats.

The effect of combined treatment with meso-2,3-dimercaptosuccinic acid (DMSA) and calcium supplementation in reducing lead absorption and enhancing lead elimination was evaluated in suckling rats under two experimental conditions: during ongoing oral lead exposure (lead acetate, 2 mg Pb kg(-1) day(-1), total dose 16 mg Pb kg(-1)) or after lead exposure (72 h after a 2-day lead exposure, total dose 12 mg Pb kg(-1) s.c.).

Combined early treatment with chelating agents DMSA and CaDTPA in acute oral cadmium exposure.

The influence of chelating agents: meso-2,3-dimercaptosuccinic acid (DMSA); calcium trisodium diethylenetriaminepentaacetate (CaDTPA) and their combination on mobilisation of cadmium (Cd) was compared in female albino rats. After oral Cd administration chelators were applied either orally (DMSA) or intraperitoneally (CaDTPA) at various short time intervals after Cd. Three experiments were carried out with four treatment groups in each: 1) Cd (control); 2) Cd+DMSA; 3) Cd+CaDTPA; 4) Cd+DMSA+CaDTPA.

Ascorbic acid supplementation does not improve efficacy of meso-dimercaptosuccinic acid treatment in lead-exposed suckling rats.

It was suggested that ascorbic acid as a natural chelating agent can influence lead toxicokinetics and improve chelating properties of dimercaptosuccinic acid (DMSA) in adult rats. In this paper potential benefits of ascorbic acid supplementation, alone or combined with DMSA, in decreasing lead retention in suckling rats were evaluated. Such data in young mammals are not available.

Effect of dietary calcium on cadmium absorption and retention in suckling rats.

The effect of calcium supplementation on absorption and retention of cadmium in the suckling period was evaluated in Wistar rat pups of both sexes. Animals were maintained in the litters with the mother rats and supplemented with 1%, 3% or 6% calcium (as CaHPO4 x 2H2O) in cow's milk by artificial feeding from day of birth 6 through 14. All rats were exposed to cadmium (as CdCl2 x H2O) either orally or parenterally.