FE 200 440: a selective oxytocin antagonist
on the term-pregnant human uterus

Nilsson L, Reinheimer T, Steinwall M, Akerlund M.
Department of Obstetrics and Gynecology,
Lund University Hospital, Sweden..
BJOG. 2003 Nov;110(11):1025-8


OBJECTIVE: To compare a newly developed oxytocin antagonist, FE 200 440, with atosiban and ANTAG III, as to potency and selectivity of inhibitory effects on oxytocin- and vasopressin-induced myometrial responses. FE 200 440 has high affinity for the human cloned oxytocin receptor, approximately 300-fold that for the vasopressin V(1a) receptor, whereas atosiban binds well to both receptors. DESIGN: In vitro study of human myometrial contractility.The Research Laboratory of the Department of Obstetrics and Gynecology, Lund University Hospital, Sweden. PARTICIPANTS: Forty-seven term-pregnant women not in labour who were delivered by caesarean section. INTERVENTIONS: Concentration-response curves with oxytocin and arginine vasopressin on isolated myometrial strips were recorded in control experiments, in the presence of atosiban in concentrations of 25, 250 and 750 nmol/L, and after pretreatment with ANTAG III and FE 200 440, both in concentrations of 2.5, 25 and 250 nmol/L.pA(2) values (i.e. an index of inhibitory action). RESULTS: With oxytocin as the agonist, the median pA(2) values for atosiban, ANTAG III and FE 200 440 were 10.6, 9.5 and 8.3, respectively. With vasopressin as the agonist, the pA(2) values for atosiban and ANTAG III were 8.8 and 8.7, whereas no inhibitory effect of FE 200 440 was seen in five out of six experiments. CONCLUSION: The new analogue FE 200 440 is a selective oxytocin antagonist and, in contrast to atosiban and ANTAG III, has practically no effect on vasopressin-induced contractions of isolated term-pregnant human myometrium.
Cuddle hormone
The power of love
Oxytocin and voles
Oxytocin and drugs
Oxytocin: structure
Oxytocin and estradiol
Hyper-reactive HPA rats
The evolution of emotion
The oxytocin receptor system
Oxytocin and social interaction
Oxytocin, addiction and the science of love

and further reading

Future Opioids
BLTC Research
Utopian Surgery?
The Abolitionist Project
The Hedonistic Imperative
The Reproductive Revolution
Critique of Huxley's Brave New World

The Good Drug Guide
The Good Drug Guide

The Responsible Parent's Guide
To Healthy Mood Boosters For All The Family