Related Experiment Videos
Dopamine receptors influence vasoactive intestinal peptide release from turkey hypothalamic explants
Y Chaiseha1, O M Youngren, M E el Halawani
1Department of Animal Science, University of Minnesota, St. Paul, Minn. 55108, USA.
Neuroendocrinology
|June 1, 1997
Summary
Dopamine (DA) influences prolactin (PRL) secretion in birds, partly through vasoactive intestinal peptide (VIP). This study found DA stimulates VIP release via D1 receptors and inhibits it via D2 receptors in turkey hypothalamus.
Area of Science:
- Neuroendocrinology
- Avian Physiology
Background:
- Vasoactive intestinal peptide (VIP) is a key prolactin-releasing factor (PRF) in avian species.
- Dopamine (DA) has a complex role, both stimulating and inhibiting prolactin (PRL) secretion.
Purpose of the Study:
- To investigate the role of dopamine receptors in regulating VIP release in the turkey hypothalamus.
- To elucidate the specific dopaminergic pathways influencing VIP secretion.
Main Methods:
- Utilized perifusion of turkey hypothalamic explants.
- Administered dopamine and its agonists/antagonists to assess VIP release.
- Employed specific D1 and D2 dopamine receptor antagonists and agonists.
Main Results:
- Dopamine dose-dependently stimulated VIP release.
- The D1 antagonist (R+)-SCH-23390 HCl blocked DA-induced VIP release.
- The D2 antagonist S(-)-eticlopride HCl stimulated VIP release independently.
- The D1 agonist (+)-SKF-38393 HCl increased VIP release, partially inhibited by the D2 agonist R(-)-NPA HCl.
Conclusions:
- VIP secretion in the turkey hypothalamus is regulated by opposing actions of D1 (stimulatory) and D2 (inhibitory) dopamine receptors.
- These findings contribute to understanding neuroendocrine control of PRL secretion in birds.