Collect. Czech. Chem. Commun. 1991, 56, 939-943

Comparison of binding affinities of a series of oxytocin analogues to uterine and mammary gland receptors and their biological potencies

Jiřina Slaninováa, Mario Hackenbergb and Falk Fahrenholzb

a Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6, Czechoslovakia
b Max-Planck-Institute of Biophysics, Kennedy Allee 70, Frankfurt a.M. 70, F.R.G.


The affinity of 12 oxytocin analogues of similar structure but differences in conformational freedom and agonistic and antagonistic properties to receptors in guinea pig uterus and rat mammary gland membrane preparations was determined by competitive binding experiments using tritiated oxytocin. The values obtained for the apparent dissociation constant KD were compared to the values of biological activities from classical pharmacological tests ( uterotonic test in vitro and galactogogic test in vivo).