PMID- 24344901
OWN - NLM
STAT- MEDLINE
DCOM- 20141015
LR  - 20141120
IS  - 1365-2826 (Electronic)
IS  - 0953-8194 (Linking)
VI  - 26
IP  - 2
DP  - 2014 Feb
TI  - Expression of CaV 2.2 and splice variants of CaV 2.1 in oxytocin- and 
      vasopressin-releasing supraoptic neurones.
PG  - 100-10
LID - 10.1111/jne.12127 [doi]
AB  - The magnocellular neurosecretory cells (MNCs) release vasopressin (VP) and 
      oxytocin (OT) from their axon terminals into the circulation and from their 
      somata and dendrites to exert paracrine effects on other MNCs. MNCs express 
      several types of voltage-gated Ca(2+) channels, including Ca(V)2.1 and Ca(V)2.2. 
      These two channels types are similar in structure and function in other cells, 
      but although influx of Ca(2+) through Ca(V)2.2 triggers the release of both OT 
      and VP into the circulation, Ca(V)2.1 is involved in stimulating the release of 
      VP but not OT. Release of OT from MNC somata is also triggered by Ca(V)2.2 but 
      not Ca(V)2.1. These observations could be explained by differences in the level 
      of expression of Ca(V)2.1 in VP and OT MNCs or by differences in the way that the 
      two channels interact with the exocytotic apparatus. We used immunohistochemistry 
      to confirm earlier work suggesting that MNCs express variants of Ca(V)2.1 lacking 
      portions of an internal loop that enables the channels to interact with synaptic 
      proteins. We used an antibody that would recognise both the full-length Ca(V)2.1 
      and the deletion variants to show that OT MNCs express fewer Ca(V)2.1 channels 
      than do VP MNCs in both somata and axon terminals. We used the reverse 
      transcriptase-polymerase chain reaction and immunocytochemistry to test whether 
      MNCs express similar deletion variants of Ca(V)2.2 and were unable to find any 
      evidence to support this. Our data suggest that the different roles that Ca(V)2.1 
      and Ca(V)2.2 play in MNC secretion may be a result of the different levels of 
      expression of Ca(V)2.1 in VP and OT MNCs, as well as the expression in MNCs of 
      deletion variants of Ca(V)2.1 that do not interact with exocytotic proteins and 
      therefore may be less likely to mediate exocytotic release.
CI  - (c) 2014 British Society for Neuroendocrinology.
FAU - Wang, D
AU  - Wang D
AD  - Department of Physiology, College of Medicine, University of Saskatchewan, 
      Saskatoon, Canada.
FAU - Fisher, T E
AU  - Fisher TE
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Neuroendocrinol
JT  - Journal of neuroendocrinology
JID - 8913461
RN  - 0 (Cacna1b protein, rat)
RN  - 0 (Calcium Channels, N-Type)
RN  - 0 (voltage-dependent calcium channel (P-Q type))
RN  - 11000-17-2 (Vasopressins)
RN  - 50-56-6 (Oxytocin)
SB  - IM
MH  - Animals
MH  - Calcium Channels, N-Type/genetics/*metabolism
MH  - Male
MH  - Neurons/*metabolism
MH  - Oxytocin/metabolism
MH  - *RNA Splicing
MH  - Rats
MH  - Rats, Long-Evans
MH  - Reverse Transcriptase Polymerase Chain Reaction
MH  - Supraoptic Nucleus/cytology/*metabolism
MH  - Vasopressins/*metabolism
OTO - NOTNLM
OT  - Ca2+ channels
OT  - oxytocin
OT  - splice variants
OT  - supraoptic
OT  - vasopressin
EDAT- 2013/12/19 06:00
MHDA- 2014/10/16 06:00
CRDT- 2013/12/19 06:00
PHST- 2013/09/05 00:00 [received]
PHST- 2013/11/25 00:00 [revised]
PHST- 2013/12/12 00:00 [accepted]
PHST- 2013/12/19 06:00 [entrez]
PHST- 2013/12/19 06:00 [pubmed]
PHST- 2014/10/16 06:00 [medline]
AID - 10.1111/jne.12127 [doi]
PST - ppublish
SO  - J Neuroendocrinol. 2014 Feb;26(2):100-10. doi: 10.1111/jne.12127.