PMID- 33711228
OWN - NLM
STAT- MEDLINE
DCOM- 20210811
LR  - 20210811
IS  - 1421-9778 (Electronic)
IS  - 1015-8987 (Linking)
VI  - 55
IP  - S1
DP  - 2021 Mar 13
TI  - Vasopressin Neurons Respond to Hyperosmotic Stimulation with Regulatory Volume 
      Increase and Secretory Volume Decrease by Activating Ion Transporters and Ca(2+) 
      Channels.
PG  - 119-134
LID - 10.33594/000000342 [doi]
AB  - BACKGROUND/AIMS: Arginine vasopressin (AVP) neurons play an important role for 
      sensing a change in the plasma osmolarity and thereby responding with regulated 
      AVP secretion in order to maintain the body fluid homeostasis. The osmo-sensing 
      processes in magnocellular neurosecretory cells (MNCs) including AVP and oxytocin 
      (OXT) neurons of the hypothalamus were reported to be coupled to sustained 
      osmotic shrinkage or swelling without exhibiting discernible cell volume 
      regulation. Since increasing evidence has shown some important differences in 
      properties between AVP and OXT neurons, osmotic volume responses are to be 
      reexamined with distinguishing these cell types from each other. We previously 
      reported that AVP neurons identified by transgenic expression of enhanced green 
      fluorescence protein (eGFP) possess the ability of regulatory volume decrease 
      (RVD) after hypoosmotic cell swelling. Thus, in the present study, we examined 
      the ability of regulatory volume increase (RVI) after hyperosmotic cell shrinkage 
      in AVP neurons. METHODS: Here, we used eGFP-identified AVP neurons acutely 
      dissociated from AVP-eGFP transgenic rats. We performed single-cell size 
      measurements, cytosolic RT-PCR analysis, AVP secretion measurements, and 
      patch-clamp studies. RESULTS: The AVP neurons were found to respond to a 
      hyperosmotic challenge with physiological cell shrinkage caused by massive 
      secretion of AVP, called a secretory volume decrease (SVD), superimposed onto 
      physical osmotic cell shrinkage, and also to exhibit the ability of RVI coping 
      with osmotic and secretory cell shrinkage. Furthermore, our pharmacological and 
      molecular examinations indicated that AVP secretion and its associated SVD event 
      are triggered by activation of T-type Ca(2+) channels, and the RVI event is 
      attained by parallel operation of Na(+)/H(+) exchanger and Cl(-)/HCO(3)(-) anion 
      exchanger. CONCLUSION: Thus, it is concluded that AVP neurons respond to 
      hyperosmotic stimulation with the regulatory volume increase and the secretory 
      volume increase by activating ion transporters and Ca(2+) channels, respectively.
CI  - (c) Copyright by the Author(s). Published by Cell Physiol Biochem Press.
FAU - Sato-Numata, Kaori
AU  - Sato-Numata K
AD  - Japan Society for the Promotion of Science, Tokyo, Japan.
AD  - Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan.
FAU - Numata, Tomohiro
AU  - Numata T
AD  - Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan.
FAU - Ueta, Yoichi
AU  - Ueta Y
AD  - Department of Physiology, School of Medicine, University of Occupational and 
      Environmental Health, Fukuoka, Japan.
FAU - Okada, Yasunobu
AU  - Okada Y
AD  - National Institute for Physiological Sciences, Okazaki, Japan, okada@nips.ac.jp.
AD  - Department of Physiology, School of Medicine, Aichi Medical University, Nagakute, 
      Japan.
AD  - Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
LA  - eng
GR  - 18J40103/Grants-in-Aid for Scientific Research (KAKENHI) from the Japan Society 
      for the Promotion of Science/Japan
GR  - Grant of The Clinical Research Promotion Foundation (2020)/Japan
PT  - Journal Article
PT  - Review
PL  - Germany
TA  - Cell Physiol Biochem
JT  - Cellular physiology and biochemistry : international journal of experimental 
      cellular physiology, biochemistry, and pharmacology
JID - 9113221
RN  - 0 (Calcium Channels)
RN  - 0 (enhanced green fluorescent protein)
RN  - 11000-17-2 (Vasopressins)
RN  - 147336-22-9 (Green Fluorescent Proteins)
RN  - 50-56-6 (Oxytocin)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Calcium/*metabolism
MH  - Calcium Channels/metabolism
MH  - Green Fluorescent Proteins/genetics/metabolism
MH  - Humans
MH  - Neurons/*metabolism
MH  - Oxytocin/*metabolism
MH  - Real-Time Polymerase Chain Reaction
MH  - Vasopressins/*metabolism
OTO - NOTNLM
OT  - Vasopressin neuron; Regulatory volume increase; Secretory volume decrease; 
      Calcium channel; Hyperosmotic stimulation
COIS- The authors have no conflicts of interest to declare.
EDAT- 2021/03/13 06:00
MHDA- 2021/08/12 06:00
CRDT- 2021/03/12 17:24
PHST- 2021/02/22 00:00 [accepted]
PHST- 2021/03/12 17:24 [entrez]
PHST- 2021/03/13 06:00 [pubmed]
PHST- 2021/08/12 06:00 [medline]
AID - 10.33594/000000342 [doi]
PST - ppublish
SO  - Cell Physiol Biochem. 2021 Mar 13;55(S1):119-134. doi: 10.33594/000000342.