Nitric oxide induced polarization of myometrium cells plasmalemma revealed by application of fluorescent dye 3,3′-dihexyloxacarbocyanine

Abstract

The fluorescence probe 3,3'-dihexyloxacarbocyanine was employed to estimate NO-induced changes of myometrium cells plasma membrane and mitochondria membrane potential by the methods of flow cytometry and spectrofluorimetry. The donors of NO, sodium nitroprusside and sodium nitrite were shown to increase the plasma membrane potential. The polarization of the plasma membrane exhibited by applied nitro-compounds was appreciable at physiologically significant concentrations of extracellular Ca2+. The rise of membrane potential has not been achieved as dihydropyridine-sensitive Ca2+-channels were blocked by nitrendipine or nonselective inhibitors of K+ channels, 4-aminopyridine, and tetraethylammonium. Nitro compounds-induced inhibition of high-potassium membrane depolarization was time-dependent. In conclusion, NO caused the increase in membrane potential of myometrium cells at the state of functional rest due to the stimulation of Ca2+-dependent K+-permeability of the plasma membrane and counteracted membrane depolarization thus, suggesting the increased susceptibility of myocytes to myoconstriction factors.