Stanniocalcin 1 prevents cytosolic Ca2+ overload and cell hypercontracture in cardiomyocytes.
BACKGROUND
The aim of the present study was to examine whether stanniocalcin 1 (STC1) affects cardiomyocytes under physiological or pathophysiological conditions.


RESULTS
Using fresh isolated rat cardiomyocytes, the effects of STC1 on cell hypercontracture, cell shortening and Ca(2+) transients were measured after exposing the cells to ouabain. STC1 alone did not affect cell shortening or the Ca(2+) transient. Exposure to ouabain significantly increased the fraction of hypercontractured cells (40.5+/-1.4% vs 3.5+/-1.7% in the control, p<0.01). However, treatment with STC1 decreased the percentage of cell hypercontracture that was induced by ouabain, in a concentration-dependent manner (17.4+/-2.6% at 2.5 nmol/L STC1, p<0.01). Moreover, STC1 prevented the increase in diastolic intracellular Ca(2+) level that was induced by ouabain (-5.3+/-2.7% vs 7.9+/-3.7% induced by ouabain, p<0.05; -15.3+/-5.1% in the control) in the cardiomyocytes.


CONCLUSIONS
STC1 prevented the increase in diastolic Ca(2+) overload and ouabain-induced cell hypercontracture, which suggests that STC1 could effectively prevent cytosolic Ca(2+) overload and protect cardiomyocytes from pathophysiological conditions such as in the failing heart.
Koizumi
Keiichi
K
Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan. kkeiishi@yamanashi.ac.jp
Hoshiai
Minako
M
Ishida
Hideyuki
H
Ohyama
Kenji
K
Sugiyama
Hisashi
H
Naito
Atsushi
A
Toda
Takako
T
Nakazawa
Hiroe
H
Nakazawa
Shinpei
S
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002316:Cardiotonic Agents / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism*; D003971:Diastole; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation / Q000379:methods; D006023:Glycoproteins / Q000008:administration & dosage / Q000494:pharmacology*; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D010042:Ouabain / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology
D002316:Cardiotonic Agents; D006023:Glycoproteins; D011994:Recombinant Proteins; D010042:Ouabain; C051795:teleocalcin; D002118:Calcium