Identification and function of ryanodine receptor subtype 3 in non-pregnant mouse myometrial cells.
The Journal of Physiology. 2002-02-01; 538(3): 707-716
DOI: 10.1113/jphysiol.2001.013046
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1. J Physiol. 2002 Feb 1;538(Pt 3):707-16.
Identification and function of ryanodine receptor subtype 3 in non-pregnant mouse
myometrial cells.
Mironneau J(1), Macrez N, Morel JL, Sorrentino V, Mironneau C.
Author information:
(1)Laboratoire de Signalisation et Interactions Cellulaires, CNRS UMR 5017,
Université Bordeaux 2, 146 rue Léo Saignat, 33076 Bordeaux, France.
Comment in
J Physiol. 2002 Feb 1;538(Pt 3):673.
Subtype 3 of the ryanodine receptor (RYR3) is a ubiquitous Ca2+ release channel
which is predominantly expressed in smooth muscle tissues and certain regions of
the brain. We show by reverse transcription-polymerase chain reaction (RT-PCR)
that non-pregnant mouse myometrial cells expressed only RYR3 and therefore could
be a good model for studying the role of endogenous RYR3. Expression of RYR3 was
confirmed by Western blotting and immunostaining. Confocal Ca2+ measurements
revealed that in 1.7 mM extracellular Ca2+, neither caffeine nor photolysis of
caged Ca2+ were able to trigger any Ca2+ responses, whereas in the same cells
oxytocin activated propagated Ca2+ waves. However, under conditions of increased
sarcoplasmic reticulum (SR) Ca2+ loading, brought about by superfusing myometrial
cells in 10 mM extracellular Ca2+, all the myometrial cells responded to caffeine
and photolysis of caged Ca2+, indicating that it was possible to activate RYR3.
The caffeine-induced Ca2+ responses were inhibited by intracellular application
of an anti-RYR3-specific antibody. Immunodetection of RYR3 with the same antibody
revealed a rather homogeneous distribution of fluorescence in confocal cell
sections. In agreement with these observations, spontaneous or triggered Ca2+
sparks were not detected. In conclusion, our results suggest that under
conditions of increased SR Ca2+ loading, endogenous RYR3 may contribute to the
Ca2+ responses of myometrial cells.
DOI: 10.1113/jphysiol.2001.013046
PMCID: PMC2290106
PMID: 11826159 [Indexed for MEDLINE]