Action of Gaseous Nitric Oxide on Some Physical and Chemical Parameters of Human Blood Samples

Abstract

We studied the metabolic changes induced by gaseous nitric oxide in whole blood samples in vitro. Blood samples were collected from healthy donors (Nizhny Novgorod station of blood transfusion). We carried out the direct bubbling of blood samples (n = 14) with gaseous flow with NO in a special appliance. We modeled standard conditions using the apparatus “Plazon” (concentration NO 800 mcg/l). Middle power of gas flow was used. The blood sparging time was 2 min, and exposition time lasted 3 min. Every blood sample volume was 5 ml. All the parameters were controlled before and after blood processing with NO. We tested lactate dehydrogenase activity in direct and reverse reactions spectrometrically by G. A. Kochetov’s method. Aldehyde dehydrogenase activity was examined by B. M. Kershnhots’s and E. V. Serkina’s methods, superoxide dismutase—by T. V. Sirota’s technology. Total protein level was examined by modified Louri’s method. The concentration of lactate was tested with the automatic analyzer “SuperGL Ambulance”. The indices of acidbase balance and blood gases partial pressure were estimated with special analyzer “ABL-77”. Additional control of energy metabolism changes was accomplished with derivative parameters, such as coefficient of energy reaction balance and coefficient of substrate provision. Different changes of blood physical and chemical parameters are induced by NO-processing which was fixed in our experiments. There is an inhibition of erythrocytes energy metabolism, decreasing of plasma antioxidant reserves, moderate ionic disorders and of acid-base misbalance in blood samples in vitro. Besides, according to the indirect signs, the used regimen of NO-processing mainly affected erythrocytes, and stipulated methemoglobin formation. These data testify that the used dose of gaseous nitric oxide is too high for investigated human blood. In our opinion, registered negative effects of free NO may be eliminated by bound nitric oxide use (first of all in its natural form—dinitrosyl-iron complexes).