[Method for testing niacin bound activities in man].
In order to value the availability of niacin in man, it has been more suitable to test erythrocyte nicotinate-phosphoribosyltransferase and nicotinamide-phosphoribosyltransferase activities. These enzymes catalyze the production of Des-NMN and NMN from free bases. The radioactive compounds, produced from [14C] NAc and [14C] NAm, are isolated by a gel chromatography and counted in liquid scintillation. It has been observed that nicotinamide-phoshoribosyltransferase is scarcely active in human erythrocytes, while the nicotinate-phosphoribosyltransferase gives a good indication of niacin availability.
D002250:Carbon Radioisotopes; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D007700:Kinetics; D054409:Nicotinamide Phosphoribosyltransferase; D009539:Nicotinic Acids / Q000097:blood*; D010430:Pentosyltransferases / Q000097:blood*; D011865:Radioisotope Dilution Technique
D002250:Carbon Radioisotopes; D009539:Nicotinic Acids; D010430:Pentosyltransferases; D054409:Nicotinamide Phosphoribosyltransferase; C021864:nicotinate phosphoribosyltransferase
Messa a punto di un metodo per la rivelazione nell'uomo di attivita' legate alla niacina.