AVP-eGFP was significantly upregulated by hypovolemia in the parvocellular division of the paraventricular nucleus in the transgenic rats.
Kenya Sanada, Hiromichi Ueno, Tetsu Miyamoto, Kazuhiko Baba, Kentaro Tanaka, Haruki Nishimura, Kazuaki Nishimura, Satomi Sonoda, Mitsuhiro Yoshimura, Takashi Maruyama, Tatsushi Onaka, Yutaka Otsuji, Masaharu Kataoka, Yoichi Ueta
American journal of physiology. Regulatory, integrative and comparative physiology 2022 Mar 01Arginine 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.
Citation
Kenya Sanada, Hiromichi Ueno, Tetsu Miyamoto, Kazuhiko Baba, Kentaro Tanaka, Haruki Nishimura, Kazuaki Nishimura, Satomi Sonoda, Mitsuhiro Yoshimura, Takashi Maruyama, Tatsushi Onaka, Yutaka Otsuji, Masaharu Kataoka, Yoichi Ueta. AVP-eGFP was significantly upregulated by hypovolemia in the parvocellular division of the paraventricular nucleus in the transgenic rats. American journal of physiology. Regulatory, integrative and comparative physiology. 2022 Mar 01;322(3):R161-R169
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PMID: 35018823
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