PMID- 18047553
OWN - NLM
STAT- MEDLINE
DCOM- 20080425
LR  - 20151119
IS  - 1365-2826 (Electronic)
IS  - 0953-8194 (Linking)
VI  - 20
IP  - 2
DP  - 2008 Feb
TI  - Chronic osmotic stimuli increase salusin-beta-like immunoreactivity in the rat 
      hypothalamo-neurohypophyseal system: possible involvement of salusin-beta on 
      [Ca2+]i increase and neurohypophyseal hormone release from the axon terminals.
PG  - 207-19
AB  - Salusin-alpha and -beta were recently discovered as bioactive endogenous 
      peptides. In the present study, we investigated the effects of chronic osmotic 
      stimuli on salusin-beta-like immunoreactivity (LI) in the rat 
      hypothalamo-neurohypophyseal system. We examined the effects of salusin-beta on 
      synaptic inputs to the rat magnocellular neurosecretory cells (MNCs) of the 
      supraoptic nucleus (SON) and neurohypophyseal hormone release from both freshly 
      dissociated SONs and neurohypophyses in rats. Immunohistochemical studies 
      revealed that salusin-beta-LI neurones and fibres were markedly increased in the 
      SON and the magnocellular division of the paraventricular nucleus after chronic 
      osmotic stimuli resulting from salt loading for 5 days and dehydration for 3 
      days. Salusin-beta-LI fibres and varicosities in the internal zone of the median 
      eminence and the neurohypophysis were also increased after osmotic stimuli. 
      Whole-cell patch-clamp recordings from rat SON slice preparations showed that 
      salusin-beta did not cause significant changes in the excitatory and inhibitory 
      postsynaptic currents of the MNCs. In vitro hormone release studies showed that 
      salusin-beta evoked both arginine vasopressin (AVP) and oxytocin release from the 
      neurohypophysis, but not the SON. In our hands, in the neurohypophysis, a 
      significant release of AVP and oxytocin was observed only at concentrations from 
      100 nm and above of salusin-beta. Low concentrations below 100 nm were 
      ineffective both on AVP and oxytocin release. We also measured intracellular 
      calcium ([Ca(2+)](i)) increase induced by salusin-beta on freshly-isolated single 
      nerve terminals from the neurohypophysis devoid of pars intermedia. Furthermore, 
      this salusin-beta-induced [Ca(2+)](i) increase was blocked in the presence of 
      high voltage activated Ca(2+)channel blockers. Our results suggest that 
      salusin-beta may be involved in the regulation of body fluid balance by 
      stimulating neurohypophyseal hormone release from nerve endings by an 
      autocrine/paracrine mechanism.
FAU - Saito, T
AU  - Saito T
AD  - Department of Physiology, School of Medicine, University of Occupational and 
      Environmental Health, Kitakyushu, Japan.
FAU - Dayanithi, G
AU  - Dayanithi G
FAU - Saito, J
AU  - Saito J
FAU - Onaka, T
AU  - Onaka T
FAU - Urabe, T
AU  - Urabe T
FAU - Watanabe, T X
AU  - Watanabe TX
FAU - Hashimoto, H
AU  - Hashimoto H
FAU - Yokoyama, T
AU  - Yokoyama T
FAU - Fujihara, H
AU  - Fujihara H
FAU - Yokota, A
AU  - Yokota A
FAU - Nishizawa, S
AU  - Nishizawa S
FAU - Hirata, Y
AU  - Hirata Y
FAU - Ueta, Y
AU  - Ueta Y
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20071128
PL  - United States
TA  - J Neuroendocrinol
JT  - Journal of neuroendocrinology
JID - 8913461
RN  - 0 (Intercellular Signaling Peptides and Proteins)
RN  - 0 (Pituitary Hormones, Posterior)
RN  - 0 (salusin-beta, rat)
RN  - 113-79-1 (Arginine Vasopressin)
RN  - 451W47IQ8X (Sodium Chloride)
RN  - 50-56-6 (Oxytocin)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Arginine Vasopressin/metabolism
MH  - Calcium/*metabolism
MH  - Excitatory Postsynaptic Potentials/drug effects
MH  - Hypothalamo-Hypophyseal System/drug effects/*metabolism/physiology
MH  - Immunohistochemistry
MH  - Inhibitory Postsynaptic Potentials/drug effects
MH  - Intercellular Signaling Peptides and Proteins/*metabolism/pharmacology
MH  - Intracellular Membranes/metabolism
MH  - Male
MH  - Osmolar Concentration
MH  - Osmosis
MH  - Oxytocin/metabolism
MH  - Patch-Clamp Techniques
MH  - Pituitary Gland, Posterior/drug effects/*metabolism/physiology
MH  - Pituitary Hormones, Posterior/*metabolism
MH  - Presynaptic Terminals/metabolism
MH  - Rats
MH  - Rats, Wistar
MH  - Sodium Chloride/*pharmacology
MH  - Supraoptic Nucleus/drug effects/metabolism
EDAT- 2007/12/01 09:00
MHDA- 2008/04/26 09:00
CRDT- 2007/12/01 09:00
PHST- 2007/12/01 09:00 [pubmed]
PHST- 2008/04/26 09:00 [medline]
PHST- 2007/12/01 09:00 [entrez]
AID - JNE1632 [pii]
AID - 10.1111/j.1365-2826.2007.01632.x [doi]
PST - ppublish
SO  - J Neuroendocrinol. 2008 Feb;20(2):207-19. doi: 10.1111/j.1365-2826.2007.01632.x. 
      Epub 2007 Nov 28.