The Effect of Dopamine Secreted by the Brain into the Systemic Circulation on Prolactin Synthesis by the Pituitary gland in Ontogenesis

This research was aimed at studying the brain’s endocrine function in ontogenesis. It has been previ-ously shown in our laboratory that the brain serves as the source of dopamine in the systemic circulation of rats prior to the formation of the blood-brain barrier. This paper provides direct evidence that dopamine secreted by the brain directly into the systemic circulation in this period of ontogenesis has an inhibitory effect on prol-actin secretion by pituitary cells. These results provide the basis for a fundamentally new understanding of the brain’s role in the neuroendocrine regulation of the development and function of peripheral target organs and, particularly in this study, the pituitary gland.