Collect. Czech. Chem. Commun. 1979, 44, 2702-2709

The preparation and metabolic fate of tritiated Nα-acetyl[2-O-methyltyrosine]oxytocin - An inhibitor of the uterotonic action of oxytocin

Vera Bojanovska, Tomislav Bartha, Bohuslav Černýb, Karel Hauzera and Karel Jošta

a Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6
b Isotope Laboratory of Biological Institutes, Czechoslovak Academy of Sciences, 142 20 Prague 4


An inhibitor of the uterotonic action of oxytocin-[CH3CO-3H] [2-O-methyltyrosine]oxytocin - having biological activity and a specific radioactivity of 3-7 Ci/mmol was prepared by the reaction of [2-O-methyltyrosine]oxytocin with 2,2'-3H2-acetanhydride. The analogue was stable in human pregnancy serum. Chymotrypsin split the Tyr(Me)-Ile and Leu-GlyNH2 peptide bonds. In the presence of subcellular fractions of homogenates of the rat uterus and mammary gland, several metabolic products were formed from the analogue.