[PHOSPHOLIPIDS, FATTY ACIDS AND HEMOGLOBIN OF ERYTHROCYTES IN RAT BLOOD UNDER STRESS CONDITIONS (SWIMMING AT A LOW...

The phospholipid and fatty acid content of erythrocytes in rat blood was studied after exposure to stress - swimming up to drowning. This stress was found to increase the content of phospholipids cha- racteristic for the membrane outer layer (phosphatidilcholine by 13 % and sphingomyelin by 23 %). At the same time a decrease in the content of acid phospholipids belonging to membrane inner layer was ob- served (phosphatidylethanolamine by 16 %, phosphatidyl serine by 14 % and monophosphoinositide by 23 %). The data obtained indicate that erythrocyte membrane under stress conditions undergoes certain structural changes which seem to have an effect on its functional properties. At the same time it was fo- und that the content of saturated, unsaturated and ounsaturation index? of fatty acids does not undergo es- sential changes under stress exposure studied thereby, possibly, compensating maintenance of functional properties of the erythrocyte membrane under conditions of the impaired phospholipid structure. On the basis of examining absorption spectra of lipid extracts it was found that stress evokes a two-fold spectrum growth in the range of 390-410 nm appropriate to the hem. The fact of appearance of the hem in the ext- ract indicates to saponification of hemoglobin evoked by changed pH of the erythrocyte internal environ- ment. Actually, in the process of lipid extraction the hemoglobim passes into a disordered state due to the effects of not only temperature and environmental pH but also due to those of organic solvents possessing lower, than water, ability to form hydrogen bonds. Probably, transesterification of a minor portion of phospholipids occurs during their extraction from erythrocytes with the chloroform-methanol mixture.