Estradiol receptors mediate estradiol-induced inhibition of mitochondrial Ca^{2+} efflux in rat caudate nucleus and brain stem

Authors : SNJEZANA PETROVIC, MAJA MILOSEVIC, DANIJELA RISTICMEDIC, NATASA VELICKOVIC, DUNJA DRAKULIC, IVANA GRKOVIC, ANICA HORVAT

Pages : 328-0

Doi:10.3906/biy-1408-62

View : 18 | Download : 15

Publication Date : 2015-12-01

Article Type : Research Paper

Abstract :Our earlier studies found that in vitro estradiol modulates mitochondrial Ca2+ transport in discrete brain regions. The present study examined the role of estradiol receptors insert ignore into journalissuearticles values(ERs); in estradiol-induced inhibition of Ca^{2+} efflux from synaptosomal mitochondria isolated from rat caudate nuclei and brain stems. Radioactively labeled CaCl_2 insert ignore into journalissuearticles values(0.6?0.75 µCi ^45CaCl_{2}); was used for Ca^{2+} transport monitoring. The results revealed that in the presence of ER antagonist 7\alpha,17ß-[9[insert ignore into journalissuearticles values(4,4,5,5,5-pentafluoropentyl);sulfinyl]nonyl]estra-1,3,5insert ignore into journalissuearticles values(10);-triene-3,17-diol insert ignore into journalissuearticles values(ICI 182,780); insert ignore into journalissuearticles values(1 µmol/L);, the inhibitory effect of estradiol on mitochondrial Ca^{2+} efflux was more than 60% decreased, suggesting the involvement of ER in this mode of estradiol neuromodulatory action. When particular contributions of ER\alpha and ERß were tested, it was found that ERß agonist 2,3-bisinsert ignore into journalissuearticles values(4-hydroxy phenyl);-propionitrile insert ignore into journalissuearticles values(10 nmol/L); inhibited Ca^{2+} efflux more than 20%, while the inhibition with ER\alpha agonist 4,4?,4??-insert ignore into journalissuearticles values(4-propyl-[1H]-pyrazole-1,3,5-triyl);trisphenol insert ignore into journalissuearticles values(10 nmol/L); was about 10%, both compared to the control. Both agonists demonstrated attenuation of Ca^{2+} efflux decrease in the presence of mitochondrial Na^{+}/Ca^{2+} exchanger antagonist 7-chloro-5-insert ignore into journalissuearticles values(2-chlorophenyl);-1,5-dihyhdro-4,1-benzothiazepin-2insert ignore into journalissuearticles values(3H);-one insert ignore into journalissuearticles values(10 µmol/L);, showing interference with the inhibitory action of that agent. Our results strongly indicate ERs as the mediators of estradiol-induced mitochondrial Ca^{2+} efflux inhibition in rat caudate nucleus and brain stem synaptosomes.
Keywords : Ca^ 2 efflux, estradiol receptors, synaptosomal mitochondria, caudate nucleus, brain stem