Acta Chimica Slovaca (ACS) publishes papers on fundamental and applied aspects of chemistry, biochemistry, chemical technology, chemical engineering and process control, biotechnology and food technology. Welcome are also topics which include chemical aspects of materials, physical chemistry and chemical physics, analytical chemistry, macromolecular chemistry and biomedical engineering.

Intracellularly regulated Ca2+ influx or remnants of extracellularly activated signalling pathway in human

Boris Lakatoš *, Roman Hudec, Ľudovít Varečka

Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, 812 37- Bratislava, Slovak Republic

E-mail: *

Abstract: Phorbol-14-myristate-13-acetate (PMA) (10-7-10-6 mol/l) inhibited the Ca2+-dependent K+ efflux (the Gárdos effect - GE) induced by Ca2+, the hyperpolarisation accompanying the GE, the vanadate-induced 45Ca2+ influx, and depolarised the membrane, in vanadate-treated human red blood cells (RBC). The GE induced by propranolol (PLL) was not inhibited by PMA. Both PMA and PLL stimulated the basal 45Ca2+ influx. These results suggest that a) protein kinase C activity prevents the activation of GE by vanadate but PLL bypasses this mechanism, b) the stimulation of the Ca2+ influx by PMA and the GE inhibition are caused by the membrane depolarisation, c) the basal Ca2+ influx in human RBC is regulated in a complex manner, and d) the effect of vanadate resembles to the activation of agonist-stimulated signalling pathway in non-excitable cells.

Keywords: Human red blood cells; Ca2+ influx; Gárdos effect; Ca2+-activated K+ channel, propranolol; vanadate; PMA

Full paper in Portable Document Format: acs_0017.pdf

Acta Chimica Slovaca, Vol. 1, No. 1, 2008, pp. 180—191