[Effect of Na2H2EDTA on the viability of rats' organism during hypothermia]

Effects of C-binding Na2H2EDTA (disodium salt of ethylene diamine tetraacetic acid) on the thermal control function of muscles and respiration in anesthetized rats of the Wistar strain cooled up to deep hypothermia were studied. Experiments were performed with the use of two cooling models, i.e. in water (10 +/- 0.2 degrees C) and air (-5 +/- 1 degrees C). Intravenous injection of 1 cm3 of the 0.6% Na2H2EDTA solution at 0.25 ml/min. was made first at the brain T = 24.0 +/- 0.4 degrees C and repeated at the brain T = 20.1 +/- 0.3 degrees C. Five to six minutes following injection the electrical myoactivity and respiration rate and amplitude grew up. The control experiments with injection of physiological solution were with null results. Injection of Na2H2EDTA reduced the thermal viability lower range as concluded from the drop of no-breathing temperature threshold and increase in tolerance period till respiration standstill by 10-15 min. It is supposed that physiological functions paralyzed by continuous cooling can be recovered by reducing active calcium in blood with intravenous Na2H2EDTA. This opens up brand new vistas for application of calcium-binding substances to assist overcooled organism.