par Kleiner, Henri 
;Yager, Michèle
Référence Clinica chimica acta, 48, 3, page (299-309)
Publication Publié, 1973-10
;Yager, Michèle Référence Clinica chimica acta, 48, 3, page (299-309)
Publication Publié, 1973-10
Article révisé par les pairs
| Résumé : | Study of pregnancy serum L-cystine-di-β-naphthylamide hydrolase ("oxytocinase") by a 2-hour assay. A 2-hour assay of pregnancy L-cystine-di-β-naphthylamide hydrolase ("oxytocinase") is described. Optimal conditions of the assay are defined from enzymatic properties such as pH optimum. Km and kinetics. During the course of human pregnancy, the oxytocinase activity of maternal serum shows an exponential increase. The inhibitory action exerted by some commonly used solvents of oxytocinase substrates on enzyme activity should be taken into account. The enzymatically liberated β-naphthylamine is partially dragged down with the serum protein precipitate when the reaction is stopped by trichloracetic acid addition. This cause of error of many oxytocinase assays must be corrected by a factor which is related to the serum protein concentration in the incubation medium. The present assay is compared with previous methods. The clinical use of the oxytocinase determination is discussed. © 1973. |
