Dopamine Regulation of Swim Stress Induction of the Pituitary Intermediate Lobe Proopiomelanocortin System

1993 ◽  
Vol 58 (3) ◽  
pp. 294-302 ◽  
Author(s):  
Elizabeth A. Young ◽  
David Bronstein ◽  
Huda Akil
Keyword(s):  
Intermediate Lobe ◽  
Swim Stress ◽  
Stress Induction ◽  
Pituitary Intermediate Lobe

In vivo evidence for dopaminergic regulation of the canine pituitary intermediate lobe

1986 ◽  
Vol 113 (4) ◽  
pp. 471-478 ◽  
Author(s):  
R. J. Kemppainen ◽  
J. L. Sartin
Keyword(s):  
Dopamine Antagonist ◽  
Test Substance ◽  
Intermediate Lobe ◽  
Adrenergic Agonist ◽  
Serotonin Agonist ◽  
Dopaminergic Pathway ◽  
Pre Treatment ◽  
Pituitary Intermediate Lobe ◽  
Dopaminergic Regulation

Abstract. In order to examine regulation of pituitary intermediate lobe secretion, plasma immunoreactive (i)ACTH, cortisol, and α-MSH responses to iv bolus injections of CRF, quipazine maleate (serotonin agonist), isoproterenol (β-adrenergic agonist) or haloperidol (dopamine antagonist) were determined in conscious, unrestrained dogs. Endocrine responses to these test substances were also determined in dogs pre-treated with dexamethasone. Administration of one or more doses of each test substance resulted in significant elevations in plasma iACTH and cortisol concentrations. Only haloperidol injection caused significant increases in plasma iα-MSH. Following dexamethasone pre-treatment, plasma iACTH and cortisol increases in response to all test substances were considerably reduced or abolished. Dexamethasone did not alter baseline or haloperidol-stimulated plasma ia-MSH concentrations. However, infusion of bromocriptine mesylate (dopamine agonist) in combination with dexamethasone pre-treatment reduced the plasma iα-MSH response to haloperidol. We conclude that a dopaminergic pathway is important in the in vivo regulation of pituitary intermediate lobe activity in dogs.

scholarly journals Regulation of pro-opiomelanocortin synthesis by dopamine and cAMP in the amphibian pituitary intermediate lobe.

1985 ◽  
Vol 260 (15) ◽  
pp. 8956-8963
Author(s):  
Y P Loh ◽  
B Myers ◽  
B Wong ◽  
D C Parish ◽  
M Lang ◽  
...  
Keyword(s):  
Intermediate Lobe ◽  
Pituitary Intermediate Lobe

scholarly journals SOX2 is required independently in both stem and differentiated cells for pituitary tumorigenesis in p27 null mice

2020 ◽  
Author(s):  
Veronica Moncho-Amor ◽  
Probir Chakravarty ◽  
Christophe Galichet ◽  
Ander Matheu ◽  
Robin Lovell-Badge ◽  
...  
Keyword(s):  
Mapk Pathway ◽  
Regulatory Region ◽  
Lineage Tracing ◽  
Intermediate Lobe ◽  
Loss Of Function ◽  
Cellular Origin ◽  
Differentiated Cells ◽  
Pituitary Tumorigenesis ◽  
Cellular Context ◽  
Pituitary Intermediate Lobe

AbstractLoss of P27 predominantly results in development of murine pituitary intermediate lobe (IL) tumours. We previously showed that the pleiotropic protein P27 can drive repression of the transcription factor Sox2. This interaction plays an important role during development of p27-/- IL tumours because loss of one copy of Sox2 diminishes tumorigenesis. Here, we have explored the cellular origin and mechanisms underlying melanotroph tumorigenesis in p27-/- IL. We show that IL hyperplasia is associated with reduced cellular differentiation, while levels of SOX2 increase in both stem cells (SC) and melanotrophs. Using loss-of-function and lineage tracing approaches, we demonstrate that SOX2 is required cell-autonomously in p27-/- melanotrophs and SCs for tumorigenesis. This is supported by studies deleting the Sox2 regulatory region 2 (Srr2), which is the target of P27 repressive action. Single cell transcriptomic analysis reveals that activation of a SOX2-dependent MAPK pathway in SCs is important for p27-/- tumorigenesis. Our data highlight different roles of SOX2 following loss of p27, according to the cellular context. Furthermore, we uncover a tumor-promoting function for SCs, which is SOX2-dependant. In conclusion, our results imply that targeting SCs, in addition to tumour cells themselves, may represent an efficient anti-tumoral strategy in certain contexts.

Dopamine D2 receptor stimulation alters G-protein expression in rat pituitary intermediate lobe melanotropes

Endocrine ◽  
1997 ◽  
Vol 6 (3) ◽  
pp. 325-333 ◽  
Author(s):  
Scott A. Sands ◽  
Daniel S. Dickerson ◽  
Stephen J. Morris ◽  
Bibie M. Chronwall
Keyword(s):  
Protein Expression ◽  
G Protein ◽  
Dopamine D2 Receptor ◽  
D2 Receptor ◽  
Intermediate Lobe ◽  
Receptor Stimulation ◽  
Dopamine D2 ◽  
Rat Pituitary ◽  
Pituitary Intermediate Lobe
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