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International Journal of Physiology and Pathophysiology
SJR: 0.116

ISSN Imprimer: 2155-014X
ISSN En ligne: 2155-0158

Archives: Volume 1, 2010 to Volume 9, 2018

International Journal of Physiology and Pathophysiology

DOI: 10.1615/IntJPhysPathophys.v6.i3.60
pages 221-230

The Role of Calcium Uniporter in Calcium Homeostasis of Extraorbital Lacrimal Gland Secretory Cells

Anna B. Kotliarova
Bogomolets Institute of Physiology, NASU, Kyiv, Ukraine
Volodymyr M. Merlavsky
Ivan Franko National University of L'viv, Ukraine
Olga M. Dorosh
Ivan Franko National University of L'viv, Ukraine
Volodymyr V. Manko
Ivan Franko National University, Lviv, Ukraine

RÉSUMÉ

The role of mitochondrial calcium-uniporter in the control of calcium homeostasis, and correlations of calcium-uniporter with other calcium-transport systems of the rat extraorbital lacrimal gland secretory cells were studied. The experiments were performed on intact and digitonin-permeabilized cells. The interdependence of calcium-uniporter and the operation of other calcium-transporting systems were assessed on the basis of the inhibitors/agonists effects additivity, the action of which was accompanied by a decrease in Ca2+ content in the gland cells. It has been revealed that simultaneous inhibition of the calcium pump in the sarco/endoplasmic reticulum (SERCA) and mitochondrial calcium-uniporter results in a passive release of Ca2+ from different calcium stores, since the effects of the inhibitors of calcium-transport systems (thapsigargin and ruthenium red, respectively) were additive. Similarly, the effects of activation of the inositol-1, 4, 5-trisphosphate receptors (IP3Rs) and inhibition of mitochondrial calcium-uniporter were additive. In contrast, the effects of ryanodine and ruthenium red on the Ca2+ content in cells were non-additive. In addition, ryanodine at concentrations 1 − 3 µM reduced respiration rate of studied cells in a dose-dependent manner, and the effect was persisted in cells pre-incubated with ruthenium red or thapsigargin. Thus, besides the activation of ryanodine receptors (RyRs) in the endoplasmic reticulum, ryanodine inhibits Ca2+ influx in the mitochondrial matrix that was insensitive to ruthenium red.