“ OXY caused a dose-related increase in PRL release from dispersed AP cells and … cell cultures which was blocked by administration of the OXY antagonists [1-deaminopenicillamine, 2-O-methyltyrosine , 8-ornithine]vasotocin (dPOMeOVT) or [1-(beta-mercapto-beta,beta-… acid)2-O-methyltyrosine, 8-ornithine]vasotocin (MPOMeOVT), respectively.”