Abstract |
The neuronal mechanisms that govern prolactin (PRL) secretion in the turkey appear to involve monoaminergic systems. Considerable evidence indicates that serotonin (5-HT), acting centrally, is a potent stimulator of PRL secretion. This study, using birds actively immunized against VIP, tests the hypothesis that 5-HT stimulates PRL secretion by releasing vasoactive intestinal peptide (VIP). Nonimmunized turkeys were injected ip with saline, quipazine ( 5-HT agonist; 5 mg/kg), methysergide ( 5-HT antagonist; 8 mg/kg), or methysergide plus quipazine, and VIP-immunized birds were injected with saline or quipazine. Quipazine increased plasma PRL levels from 26.8 +/- 7.1 ng/ml at Time 0 to a peak value of 148.1 +/- 31.4 ng/ml 2 hr after infection. Pretreatment with methysergide or VIP-immunoneutralization abolished the PRL response to quipazine. Intraventricular infusion of 5-HT (1 nmol/min) caused plasma PRL to rise from a baseline of 16.3 +/- 2.6 ng/ml to 85.2 +/- 14.3 ng/ml after 30 min in nonimmunized control birds. Serotonin infusion did not induce PRL secretion in the VIP-immunized birds. These findings suggest that serotonergic stimulation of PRL secretion in the female turkey requires a functional VIPergic system.
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Authors | M E el Halawani, O M Youngren, I Rozenboim, G R Pitts, J L Silsby, R E Phillips |
Journal | General and comparative endocrinology
(Gen Comp Endocrinol)
Vol. 99
Issue 1
Pg. 69-74
(Jul 1995)
ISSN: 0016-6480 [Print] United States |
PMID | 7657159
(Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)
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Chemical References |
- Serotonin
- Vasoactive Intestinal Peptide
- Quipazine
- Prolactin
- Methysergide
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Topics |
- Animals
- Brain
(drug effects)
- Female
- Immunization
- Kinetics
- Methysergide
(pharmacology)
- Prolactin
(metabolism)
- Quipazine
(pharmacology)
- Serotonin
(administration & dosage, pharmacology)
- Turkeys
- Vasoactive Intestinal Peptide
(immunology, physiology)
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