[Stimulation of thermoregulatory and respiratory functions with the help of EDTA and EGTA during deep hypothermia in rats].

Influence of EDTA (C10H14N2Na2O8.2H2O) and EGTA (C14H24N2O10) on physiological functions homoiothermic organisms at deep hypothermia, was studied. White rats during cooling were in special sections without rigid fixing of head and limbs. In reply to intravenous introduction of EDTA and EGTA solutions, similar answers of the organisms were observed: raised breathing frequency and amplitude, intensity of electrical activity of muscles; these signs of activation of physiological functions lasted 8-10 minutes. Besides, of the 20th-30th minute after introduction of the second dose of preparations (at rectal temperature 17.1 +/- 0.5 degrees C), the secondary activation respiratory and thermoregulatory functions were registered. The termination of the cold shivering in experiments with introduction of EDTA and EGTA solutions occurred at lower temperatures in rectum and in a brain (16.7-17.3 degrees and 17.8-18.2 degrees C, resp.) than in control experiments (18.7 +/- 0.6 degrees C and 20.2 +/- 1.5 degrees C). The authors suppose that the activation of the thermoregulatory and respiratory functions is caused by a decrease in concentration of ions Ca2+ in the blood plasma.