Abstract
Ovariectomy zed rats, when transplanted with 4 anterior piluitaries (APs) to the kidney capsule for 2-3 weeks, had elevated plasma prolactin (PRL) levels (3.8-fold) and showed decreased in situ AP weights (0.62-fold) and PRL concentrations (0.63-fold). The concentrations of dopamine (DA) and oxytocin (OT) in pituitary portal plasma of hyperprolactinemic rats were increased 1.7- and 1.9-fold, respectively. However, the levels of vasoactive intestinal peptide (VIP) in pituitary portal plasma of these rats were decreased 0.31-fold. The secretion of DA, dihydroxyphenylalanine (DOPA) and OT from fetal hypothalamic cells in primary culture was increased, whereas VIP secretion from these cells was reduced in a dose-dependent fashion following PRL treatment. These data are the first in vivo and in vitro demonstration of a stimulatory action of PRL on OT release and an inhibitory action of PRL on VIP release. Furthermore, these data suggest that a subtle imbalance between the secretion of the PRL-inhibiting factor (DA) and the PRL-releasing factors (VIP and OT) during elevated systemic levels of PRL is responsible for decreased lactotrophic function.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 520-524 |
| Number of pages | 5 |
| Journal | Neuroendocrinology |
| Volume | 49 |
| Issue number | 5 |
| DOIs | |
| State | Published - 1989 |
| Externally published | Yes |
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Endocrinology
- Endocrine and Autonomic Systems
- Cellular and Molecular Neuroscience
Keywords
- DA
- DOPA
- Hypothalamic cell culture
- OT
- PRL
- Pituitary portal blood
- VTP