Chronic hyperprolactinemia causes progressive changes in hypothalamic dopaminergic and noradrenergic neurons

James W. Simpkins, Steven M. Gabriel

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

Studies were undertaken to evaluate the effects of chronic hyperprolactinemia (HYP) on catecholamine concentrations and turnover rates in brain regions of the female rat. HYP was induced by inoculation of tissue derived from the prolactin secreting MtTW15 tumor. When serum prolactin (PRL) levels were moderately elevated, medial basal hypothalamus (MBH) dopamine (DA) turnover was enhanced and DA concentrations were moderately reduced. Later, as serum PRL levels increased to greater than 10 μg/ml, DA concentrations were further reduced and DA turnover was concomitantly reduced to below pre-tumor levels. In the preoptic area-anterior hypothalamus (POA-AH), DA concentrations were reduced as PRL levels increased and this was associated with a reduction in DA turnover. Between 5 and 8 weeks of tumor growth, DA turnover remained low, but DA concentrations increased. In the neurointermediate lobe of the pituitary (NIL) the tumor reduced DA turnover at 5 weeks only. Norepinephrine (NE) turnover, but not concentration, was reduced in both the POA-AH and MBH. Surgical removal of the tumor at 5 weeks of growth reduced serum PRL levels to near normal, but MBH DA concentrations and turnover remained depressed while POA-AH and NIL DA levels and turnover increased. Despite removal of the tumor, NE turnover remained depressed in both the MBH and POA-AH. These studies indicate that severe chronic HYP causes progressive alterations in hypothalamic catecholamine neurons which are not reversed by normalization of serum PRL levels. These results suggest that chronic HYP can cause long-lasting effects on some DA and NE neuronal systems.

Original languageEnglish
Pages (from-to)271-276
Number of pages6
JournalBrain Research
Volume309
Issue number2
DOIs
StatePublished - 10 Sep 1984
Externally publishedYes

Keywords

  • MtTW15 tumor
  • dopamine
  • hyperprolactinemia
  • norepinephrine
  • prolactin
  • rat

Fingerprint

Dive into the research topics of 'Chronic hyperprolactinemia causes progressive changes in hypothalamic dopaminergic and noradrenergic neurons'. Together they form a unique fingerprint.

Cite this