The Oxytocin-Oxytocin Receptor System and Its Antagonists as Tocolytic Agents

Table 1

The most extensively studied OT antagonists and their experimental or clinical applications.

Oxytocin antagonists	Organism	Experimental or therapeutic application
(I) Peptide
1-Deamino-2-D-Tyr-(O-ethyl)-4-Thr-8-ornoxytocin (Atosiban)	Human	Clinically used tocolytic agent
d(CH2)5[Tyr(Me)^2]OVT	Animals/human cells and tissues, or both	Pharmacological tool in experimental studies of OT functions
desGly–NH2,d(CH2)5[Tyr(Me)^2,Thr^4]OVT	Animals/human cells and tissues, or both	Pharmacological tool in experimental studies of OT functions
desGly–NH2,d(CH2)5[D-Tyr^2,Thr^4]OVT	Animals/human cells and tissues, or both	Pharmacological tool in experimental studies of OT functions
d(CH2)^5,[D-Thi^2,Thr^4,Tyr–NH2^9]OVT	Animals/human cells and tissues, or both	Pharmacological tool in experimental studies of OT functions
desGly–NH2,d(CH2)5[D-Trp^2,Thr^4,Dap^5]OVT	Animals/human cells and tissues, or both	Pharmacological tool in experimental studies of OT functions
desGly–NH2,d(CH2)5[D-2-Nal^2,Thr^4]OVT	Animals/human cells and tissues, or both	Pharmacological tool in experimental studies of OT functions
desGly–NH2,d(CH2)5[2-Nal^2,Thr^4]OVT	Animals/human cells and tissues, or both	Pharmacological tool in experimental studies of OT functions
d(CH2)5[D-2-Nal^2,Thr^4,Tyr–NH2^9]OVT	Animals/human cells and tissues, or both	Pharmacological tool in experimental studies of OT functions
d(CH2)5[2-Nal^2,Thr^4,Tyr–NH2^9]OVT	Animals/human cells and tissues, or both	Pharmacological tool in experimental studies of OT functions
FE 200 400 (Barusiban)	Monkeys/human myometrial tissue	Pharmacological tool in experimental studies of OT functions
(II) Nonpeptide
GSK221149A (Retosiban)	Rats	Tocolytic action. A phase ll clinical trial for its use as a tocolytic in humans has not yet been completed
L-368,899	Animals/human cells and tissues, or both	Pharmacological tools in experimental studies of OT function. CNS effects. Inhibits spontaneous nocturnal uterine contractions in pregnant rhesus monkeys. Clinical studies discontinued
L-371,257	Animals/human cells and tissues, or both	Pharmacological tool in experimental studies of OT functions
WAY-162720	Animals/human cells and tissues, or both	Pharmacological tool in experimental studies of OT functions
SSR-126768A	Rats/human myometrial tissue	Tocolytic action in rats. Inhibits the response to OT in term human pregnant uterine sections