Heparin tritium labelling

Ultrafiltration has been used to determine the protein bound fraction of many drags, such as methadone (Wilkins et al. 1997), phenylacetate and phenylbu-tyrate (Boudoulas et al. 1996), etoposide (Robieux et al. 1997), doxorubicin and vincristine (Mayer and St-Onge 1995), disopyramide (Echize et al. 1995), and ketamine and its active metabolites (Hijazi and Boulieu 2002). Schumacher et al. (2000) have shown the applicability for the determination of erythro-cyte/plasma distribution. The method of UF has been applied in the measurement of free unaltered thyroxin or after displacement by salicylate as well after displacement by heparin in healthy people and in patients with non-thyroidal somatic illness (Faber et al. 1993). The protein binding of tritium labeled, antidiabetic repaglinide and its displacement by warfarin, furosemide, tolbutamide, diazepam, glibenclamide and nicardipine were determined by ultrafiltration (Plumetal. 2000). 

Pectic acid has been esterified with propionic anhydride and the product partially reduced with gaseous diborane. Tritium labelling has been applied to heparin by using tritium gas under an electric discharge or tritiated water in the presence of palladium black. Labelled glycosaminoglycans may also be prepared by labelling in vitro. - ... 

Heparin has been labeled by this method85 and also by platinum-catalyzed exchange with tritium gas,58 in both cases with retention of biological activity, and it is used commercially for labeling C-l of aldoses. 

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