Effect of Diterpenoid Alkaloid 14-O-Benzoiltalatizamin ON NA+/СA2+-Exchanger Smooth Muscle of Cells of an Aorta of a Rat

Na+/Ca2+-exchanger, plays an important role in maintenance of Са2+ -homeostasis in a cage and therefore regulation of its activity has special value and is provided with a number of mechanisms. Found by us ability of alkaloid 14-O-BT to inhibit reductions of smooth muscles in conditions when Na+/Са2+-exchanger works within the turned mode and transfers ions of Са2+ to MMC (the smooth muscle of cages), testifies to prospects of further research of these connections for development of effective approaches of correction of pathological states the overloads arising at Са2+. Suppression by alkaloid 14-O-BT, reductions of the preparations of an aorta of a rat induced by Krebs's solution without Na+ also is the evidence of interaction of these agents with Na+/Са2+-exchanger of SMC.

As our checked experiments, replacement of normal solution of Krebs by solution without Na+ showed, causes immediate reduction of preparations of an aorta which within 10-15 min. reaches the maximum amplitude making 70,1±2,3% of the control reduction induced 5 microns of the adrenaline (taken for 100%). In these experimental conditions, addition of a blocker potential - dependent channels Са2+ of verapamil (1 micron), was followed by reduction of force of reductions of the preparations of an aorta induced without Na+-solutions to 53,4±3,6%. Such reduction of force of reductions of the preparations of an aorta induced without Na by +-solution is explained by suppression verapamil of receipt of ions of Са2+ in SMC through potential - dependent channels Са2+.

Results of these checked  experiments convincingly testify that development of reductions of the preparations of an aorta induced without Na+-solutions in the presence of verapamil generally is provided with ions of Са2+, coming to MMC through Na+/Са2+-exchanger.

As showed our researches, in these experimental conditions alkaloid 14-O-BT considerably suppresses the reductions of preparations of an aorta induced without Na+-solutions. Thus the effect 14-O-BT had dose-dependent character and at its concentration of 10 microns force of reduction of a preparation of an aorta induced without Na+-solution decreased by 20±3%, and at its concentration of 160 microns it as much as possible suppressed reduction force for 63,9±2,8% of the control received in the presence of 1 micron of verapamil and taken for 100%.