Dopamine as a prolactin (PRL) inhibitor.
Level 5 - mechanism / opinion, no new human data
Narrative review of mechanistic, animal, and clinical literature with no new data or systematic search protocol.
PubMed 11739329 · doi:10.1210/edrv.22.6.0451
What was done
This paper reviewed the physiological mechanisms by which dopamine regulates prolactin (PRL) synthesis and secretion. It synthesized findings across molecular genetics (cloning of enzymes, transporters, and receptors), hypothalamic-pituitary portal tract signaling, transgenic animal models, and clinical pharmacological management of hyperprolactinemia.
What was found
The abstract provides no quantitative data or statistical measures. Qualitatively, it reports that dopamine from hypothalamic nerve tracts reaches the anterior pituitary through hypophysial portal vessels and binds to D2 dopamine receptors coupled to G proteins and membrane channels. This signaling cascade inhibits calcium fluxes, downregulates PRL gene expression, suppresses intrinsic lactotroph secretory activity, and inhibits lactotroph proliferation. The abstract also notes that prolactin release in humans differs in several respects from laboratory animal models and emphasizes dopamine agonists as key treatments for clinical hyperprolactinemia.
Why it matters
It outlines the fundamental neuroendocrine mechanism of tonic prolactin inhibition, explaining the physiological basis for dopamine agonist therapy in hyperprolactinemia and reproductive disorders.
Limits
The abstract describes a broad narrative review without a systematic search strategy, explicit study selection criteria, or meta-analytic pooling. No sample sizes, effect sizes, or comparative clinical outcomes are reported.
Cited by
- supports Dopamine and prolactin exist in an antagonistic or seesaw relationship in neuroendocrinological regulation.