AVP-eGFP was significantly upregulated by hypovolemia in the parvocellular division of the paraventricular nucleus in the transgenic rats.
Am J Physiol Regul Integr Comp Physiol
; 322(3): R161-R169, 2022 03 01.
Article
in English
| MEDLINE | ID: covidwho-1770007
ABSTRACT
Arginine vasopressin (AVP) is produced in the paraventricular (PVN) and supraoptic nuclei (SON). Peripheral AVP, which is secreted from the posterior pituitary, is produced in the magnocellular division of the PVN (mPVN) and SON. In addition, AVP is produced in the parvocellular division of the PVN (pPVN), where corticotrophin-releasing factor (CRF) is synthesized. These peptides synergistically modulate the hypothalamic-pituitary-adrenal (HPA) axis. Previous studies have revealed that the HPA axis was activated by hypovolemia. However, the detailed dynamics of AVP in the pPVN under hypovolemic state has not been elucidated. Here, we evaluated the effects of hypovolemia and hyperosmolality on the hypothalamus, using AVP-enhanced green fluorescent protein (eGFP) transgenic rats. Polyethylene glycol (PEG) or 3% hypertonic saline (HTN) was intraperitoneally administered to develop hypovolemia or hyperosmolality. AVP-eGFP intensity was robustly upregulated at 3 and 6 h after intraperitoneal administration of PEG or HTN in the mPVN. While in the pPVN, eGFP intensity was significantly increased at 6 h after intraperitoneal administration of PEG with significant induction of Fos-immunoreactive (-ir) neurons. Consistently, eGFP mRNA, AVP hnRNA, and CRF mRNA in the pPVN and plasma AVP and corticosterone were significantly increased at 6 h after intraperitoneal administration of PEG. The results suggest that AVP and CRF syntheses in the pPVN were activated by hypovolemia, resulting in the activation of the HPA axis.
Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Paraventricular Hypothalamic Nucleus
/
Arginine Vasopressin
/
Hypovolemia
/
Green Fluorescent Proteins
/
Hypothalamo-Hypophyseal System
Type of study:
Experimental Studies
/
Randomized controlled trials
Limits:
Animals
Language:
English
Journal:
Am J Physiol Regul Integr Comp Physiol
Journal subject:
Physiology
Year:
2022
Document Type:
Article
Affiliation country:
AJPREGU.00107.2021
Similar
MEDLINE
...
LILACS
LIS