Hypothalamic-pituitary corticotroph function after shunting of magnocellular vasopressin and oxytocin to the hypophyseal portal circulation

Endocrinology
G MakaraG Aguilera

Abstract

Surgical pituitary stalk compression (PSC) causes neural lobe denervation and development of ectopic magnocellular terminals in the external zone of the median eminence, resulting in shunting of magnocellular vasopressin (VP) and oxytocin (OT) to the pituitary portal circulation. To determine the effects of PSC on hypothalamic and pituitary function, VP and CRH receptors and POMC messenger RNA (mRNA) in the pituitary, and CRH, VP, and OT mRNA levels in the PVN were examined in 7-day PSC and sham-operated rats. Immunohistochemical staining revealed marked accumulation of immunoreactive VP in the swollen pituitary stalk and the external zone of the distal median eminence of PSC rats. Plasma ACTH and corticosterone levels were significantly increased by PSC, an effect that was attenuated by minipump infusion of desamino-[D-Arg8]-vasopressin (DDAVP) given to correct the diabetes insipidus. [3H]VP binding to anterior pituitary membranes from PSC rats was reduced by 50% compared to that in sham-operated controls, but VP V1b receptor mRNA levels measured by in situ hybridization were unchanged. Pituitary CRH receptors measured by binding autoradiography and CRH receptor mRNA levels did not change after PSC. POMC mRNA was unchanged in ...Continue Reading

Citations

Aug 28, 2003·Neuropsychopharmacology : Official Publication of the American College of Neuropsychopharmacology·Alexandra WiggerRainer Landgraf
Jun 16, 2007·The Journal of Comparative Neurology·Martin Williamson, Victor Viau
Apr 16, 1999·Endocrine Reviews·P L Dahia, A B Grossman
Mar 19, 2019·The Journal of Clinical Endocrinology and Metabolism·Anna AulinasElizabeth A Lawson
Jun 11, 1999·The Journal of Comparative Neurology·G C PanzicaP Deviche

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