Two-photon imaging of endothelin-1-mediated intracellular Ca2+ handling in smooth muscle cells of rat renal resistance arteries
O Palygin, B Miller, DV Ilatovskaya, A Sorokin… - Life sciences, 2016 - Elsevier
Life sciences, 2016•Elsevier
Abstract Aims Endothelin-1 (ET-1) is a potent vasoconstrictor which regulates the physiology
of cardiorenal system. The aim of this study was to evaluate ET-1-mediated elevation of
intracellular Ca 2+ in smooth muscle cells (SMC) of renal resistance arteries. Main methods
In in vitro studies of primary SMC, which were isolated from rat renal microvessels, the levels
of intracellular Ca 2+ were calculated from the ratio of emissions at 340 and 380 nm after
loading cells with Fura 2-AM dye. In ex vivo studies we used two-photon imaging of renal …
of cardiorenal system. The aim of this study was to evaluate ET-1-mediated elevation of
intracellular Ca 2+ in smooth muscle cells (SMC) of renal resistance arteries. Main methods
In in vitro studies of primary SMC, which were isolated from rat renal microvessels, the levels
of intracellular Ca 2+ were calculated from the ratio of emissions at 340 and 380 nm after
loading cells with Fura 2-AM dye. In ex vivo studies we used two-photon imaging of renal …
Aims
Endothelin-1 (ET-1) is a potent vasoconstrictor which regulates the physiology of cardiorenal system. The aim of this study was to evaluate ET-1-mediated elevation of intracellular Ca2 + in smooth muscle cells (SMC) of renal resistance arteries.
Main methods
In in vitro studies of primary SMC, which were isolated from rat renal microvessels, the levels of intracellular Ca2 + were calculated from the ratio of emissions at 340 and 380 nm after loading cells with Fura 2-AM dye. In ex vivo studies we used two-photon imaging of renal resistance arteries excised from rat kidneys and loaded with fluorescent Ca2 + indicator Fluo-4 AM.
Key findings
The two-photon imaging demonstrates that treatment of isolated rat renal resistance arteries with ET-1 causes a rapid increase of intracellular Ca2 + concentration in smooth muscle vasculature of these vessels. These ex vivo observations are in accordance with in vitro findings indicating that ET-1 mediates activation of TRPC channels and increases the level of intracellular Ca2 + in cultured SMC to 510 ± 83 nM.
Significance
ET-1-mediated elevation of intracellular Ca2 + is strongly linked to renal microvascular contraction and is crucial for ET-1-induced contraction of SMC. The two-photon imaging of intracellular Ca2 + in intact SMC of rat renal resistance arteries is a powerful technique which allows the detailed ex vivo analysis of intracellular Ca2 + handling by ET-1, an important player in hypertension-related kidney diseases.
Elsevier