[Pharmacokinetics of sodium selenite in human body at different levels of selenium].

Twelve health adults (6 M, 6 F) from the endemic area of Keshan disease and Kaschin-Beck's disease and 12 adults from nonaffected area were administered a single oral dose of 4 mg sodium selenite. Selenium in whole blood was determined by fluorescence spectrometry. Their basic levels of blood selenium were 64 +/- 16 and 220 +/- 20 ng.ml-1, respectively. The concentration-time data were treated by a computer with program 3P87, which revealed 2-compartment models with first order absorption and lag time. The pharmacokinetic parameters of low-Se group were T1/2g 1.8 +/- 0.6h, T1/2g 72 +/- 18 h, T1/2ka 3.2 +/- 1.8h, AUC 3,100 +/- 500 ng.h.ml-1, CL 32 +/- 7 ml.kg-1.h-1, Vc 1.45 +/- 0.19 L.kg-1, Tp 6.1 +/- 2.0 h, Cp 36 +/- 4 ng.ml-1, AUMC (S1) 130 +/- 26, VRT 174 +/- 17 h, MRT 55 +/- 4 h, and of normal-Se group were T1/2 3.4 +/- 0.7h, T1/2g 14 +/- 3 h. T1/2ka 2.3 +/- 0.6, AUC 1,420 +/- 210 ng.h.ml-1, Cl 57 +/- 7 ml.kg-1. h-1, Vc 0.54 +/- 0.09 L.kg-1, Tp 4.6 +/- 0.9h, Cp 75 +/- 5 ng.ml-1, AUMC (S1) 25 +/- 5, VRT 16 +/- 3 h, MRT 16.1 +/- 1.5 h.

[Pharmacokinetic study of sodium selenite in low-selenium rabbits].

Sodium selenite has been used for prevention and treatment of Keshan disease and Kaschin-Beck's disease. The efficacious dosage regimens of sodium selenite in low-Se human body have not been clear. A single iv or ig of sodium selenite 2.0 mg/kg was given to rabbits. Selenium in whole blood was determined fluorophotomerically. The concentration-time curve following a single iv of sodium selenite in rabbits was found to be of 3-compartment open model. The pharmacokinetic parameters were: T1/2 x 0.11 +/- 0.03 h, T1/2 alpha 6.8 +/- 2.8 h, T1/2 beta 215 +/- 35 h, Vc 0.50 +/- 0.07 L/kg, Cl 19 +/- 5 ml/(kg.h), AUC 146 +/- 26 mg.h/L. The concentration-time curve following a single ig of sodium selenite showed a pattern of 2-compartment open model. The parameters were: T1/2 kappa a 13 +/- 6 h, T1/2 alpha 3.6 +/- 1.9 h, T1/2 beta 338 +/- 107 h, Vc 2.9 +/- 1.3 L/kg, AUC 78 +/- 29 mg.h/L, Cl 27 +/- 11 ml/(kg.h). In low-Se rabbits the distribution in body was more rapid and more extensive, and the bioavailability was higher than that in normal-Se rabbits. Therefore, attention should be paid to the different levels of selenium during therapy with sodium selenite.

Immobilization of glucose oxidase and peroxidase and their application in flow-injection analysis for glucose in serum.

Glucose oxidase (GOD) and Horseradish peroxidase (HRP) were covalently coupled to alkylamine controlled pore glass by means of glutaraldehyde. About 700-800 U/g of immobilized GOD and 300-400 U/g of immobilized HRP were obtained. Some factors of affecting enzyme immobilization were discussed. The immobilized enzymes were packed into a plastic tube and used in flow-injection analysis (FIA) for glucose in serum. A good linearity range was observed for this immobilized enzyme system at 20 mg/mL to 1000 mg/dL D-glucose, the recovery was 95.4-103.5%, the within-batch imprecision was 0.8-2.2%, and the between-batch imprecision was 2.2-4.2%. More than 100 samples were measured within an hour. One enzyme column with five units of immobilized GOD and HRP, applied for 50 assays/d, has been used for more than 2 mo.