caa a22 4500 477074189 CHVBK 20180405111435.0 cr unu---uuuuu 170330e19961101xx s 000 0 eng 10.1007/BF02252852 doi (NATIONALLICENCE)springer-10.1007/BF02252852 Modulation of the membrane potential of intact guinea pig aortic endothelium [Elektronische Daten] [A. Bondarenko, V. Sagach] The role of different ion conductances in regulation of the membrane potential (MP) of resting and agonist-stimulated intact endothelium from the guinea pig aorta was investigated. Under resting conditions, the MP measured by the patch-clamp technique varied within the range from −29 to −56 mV (the mean value of −40.8 ± 8.1 mV). Blockers of anomalous (inward) rectifier potassium channels cesium (100 µM) and barium (100 µM) exerted no effect on the MP of endothelium. Superfusion of preparations with calcium-free solution and application of 2 mM nickel depolarized the endothelium. ATP (10 µM) induced hyperpolarization of endothelium with the mean amplitude of 11.4 ± 0.6 mV. The initial phase of this hyperpolarization depended on the external potassium concentration and on the state of intracellular calcium stores, whereas the prolonged phase required the presence of external calcium. In the absence of external calcium, in 25% of recordings transient hyperpolarization was followed by depolarization, which was not observed after substitution of external NaCl for choline. It was concluded that basal activity of calcium-dependent potassium channels contributes to the regulation of the MP of resting endothelium. Stimulation with ATP led to activation of calcium-dependent potassium and nonselective cationic channels. Activation of the former channels produced the initial phase of hyperpolarization, whereas activation of the second channel type evoked the prolonged phase of hyperpolarization. Plenum Publishing Corporation, 1997 Bondarenko A. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine aut Sagach V. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine aut Neurophysiology Kluwer Academic Publishers-Plenum Publishers 28/6(1996-11-01), 202-207 0090-2977 28:6<202 1996 28 11062 https://doi.org/10.1007/BF02252852 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02252852 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bondarenko A. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine aut NATIONALLICENCE 700 1- Sagach V. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine aut NATIONALLICENCE 773 0- Neurophysiology Kluwer Academic Publishers-Plenum Publishers 28/6(1996-11-01), 202-207 0090-2977 28:6<202 1996 28 11062 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer