PMID- 23850590
OWN - NLM
STAT- MEDLINE
DCOM- 20140404
LR  - 20161125
IS  - 1873-7544 (Electronic)
IS  - 0306-4522 (Linking)
VI  - 250
DP  - 2013 Oct 10
TI  - Hypertonicity increases NO production to modulate the firing rate of 
      magnocellular neurons of the supraoptic nucleus of rats.
PG  - 70-9
LID - S0306-4522(13)00573-3 [pii]
LID - 10.1016/j.neuroscience.2013.06.067 [doi]
AB  - Increases in plasma osmolality enhance nitric oxide (NO) levels in magnocellular 
      neurosecretory cells (MNCs) of the supraoptic nucleus (SON) and modulate the 
      secretion of both vasopressin (VP) and oxytocin (OT). In this paper, we describe 
      the effects of hypertonicity on the electrical properties of MNCs by focusing on 
      the nitrergic modulation of their activity in this condition. Membrane potentials 
      were measured using the patch clamp technique, in the presence of both 
      glutamatergic and GABAergic neurotransmission blockers, in coronal brain slices 
      of male Wistar rats. The recordings were first made under a control condition 
      (295 mosm/kg H2O), then in the presence of a hypertonic stimulus (330 mosm/kg 
      H2O) and, finally, with a hypertonic stimulus plus 500 muM L-Arginine or 100 muM 
      N-nitro-L-Arginine methyl ester hydrochloride (L-NAME). Hypertonicity per se 
      increased the firing frequency of the neurons. L-Arginine prevented the increase 
      in fire frequency induced by hypertonic stimulus, and L-NAME (inhibitor of nitric 
      oxide synthase) induced an additional increase in frequency when applied together 
      with the hypertonic solution. Moreover, L-Arginine hyperpolarizes the resting 
      potential and decreases the peak value of the after-hyperpolarization; both 
      effects were blocked by L-NAME and hypertonicity and/or L-NAME reduced the time 
      constant of the rising phase of the after-depolarization. These results 
      demonstrate that an intrinsic nitrergic system is part of the mechanisms 
      controlling the excitability of MNCs of the SON when the internal fluid 
      homeostasis is disturbed.
CI  - Copyright (c) 2013 IBRO. Published by Elsevier Ltd. All rights reserved.
FAU - da Silva, M P
AU  - da Silva MP
AD  - Department of Physiology, School of Medicine of Ribeirao Preto, University of Sao 
      Paulo, Avenida Bandeirantes, 3900, 14049-900 Ribeirao Preto, SP, Brazil.
FAU - Ventura, R R
AU  - Ventura RR
FAU - Varanda, W A
AU  - Varanda WA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20130711
PL  - United States
TA  - Neuroscience
JT  - Neuroscience
JID - 7605074
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Hypertonic Solutions)
RN  - 0 (Hypotonic Solutions)
RN  - 31C4KY9ESH (Nitric Oxide)
RN  - 94ZLA3W45F (Arginine)
RN  - EC 1.14.13.39 (Nitric Oxide Synthase)
RN  - V55S2QJN2X (NG-Nitroarginine Methyl Ester)
SB  - IM
MH  - Action Potentials/drug effects/physiology
MH  - Animals
MH  - Arginine/pharmacology
MH  - Basal Nucleus of Meynert/cytology/*metabolism
MH  - Electrophysiological Phenomena/physiology
MH  - Enzyme Inhibitors/pharmacology
MH  - Hypertonic Solutions/pharmacology
MH  - Hypotonic Solutions/pharmacology
MH  - In Vitro Techniques
MH  - Kinetics
MH  - NG-Nitroarginine Methyl Ester/pharmacology
MH  - Neurons/*metabolism
MH  - Nitric Oxide/*biosynthesis
MH  - Nitric Oxide Synthase/antagonists & inhibitors
MH  - *Osmolar Concentration
MH  - Patch-Clamp Techniques
MH  - Rats
MH  - Rats, Wistar
MH  - Supraoptic Nucleus/cytology/*metabolism
OTO - NOTNLM
OT  - 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid
OT  - 4-amino-5-methylamino-2',7' diaminofluorescein-FM
OT  - 6-cyano-7-nitroquinoxaline-2,3-dione
OT  - ACSF
OT  - ADP
OT  - AHP
OT  - CNQX
OT  - DAF-FM
OT  - DMSO
OT  - EGTA
OT  - HEPES
OT  - MNCs
OT  - N-nitro-l-Arginine methyl ester hydrochloride
OT  - NADPH
OT  - NO
OT  - NOS
OT  - OT
OT  - SON
OT  - VP
OT  - after-depolarization potential
OT  - after-hyperpolarization potential
OT  - artificial cerebro spinal fluid
OT  - dimethylsulfoxide
OT  - electrophysiology
OT  - ethylene glycol tetraacetic acid
OT  - extracellular tonicity
OT  - l-NAME
OT  - magnocellular neurons
OT  - magnocellular neurosecretory cells
OT  - nicotinamide adenine dinucleotide phosphate
OT  - nitric oxide
OT  - nitric oxide synthase
OT  - oxytocin
OT  - supraoptic nucleus
OT  - vasopressin
EDAT- 2013/07/16 06:00
MHDA- 2014/04/05 06:00
CRDT- 2013/07/16 06:00
PHST- 2013/01/26 00:00 [received]
PHST- 2013/06/10 00:00 [revised]
PHST- 2013/06/29 00:00 [accepted]
PHST- 2013/07/16 06:00 [entrez]
PHST- 2013/07/16 06:00 [pubmed]
PHST- 2014/04/05 06:00 [medline]
AID - S0306-4522(13)00573-3 [pii]
AID - 10.1016/j.neuroscience.2013.06.067 [doi]
PST - ppublish
SO  - Neuroscience. 2013 Oct 10;250:70-9. doi: 10.1016/j.neuroscience.2013.06.067. Epub 
      2013 Jul 11.