THE CHANGES OF CONTENT, STRUCTURE AND CHA RGE OF RAT PLASMA-LIPOPROTEINS DURING LONG-TERM COLD-EXPOSURE

The paper shows the results of complex investigation with the fluoresc ence techniques, electrophoresis. a.o. methods of rat plasma lipoprote ins in various terms (1 day - 49 days) of cold exposure (+5 degrees C) . There was the quantitative increase of the common fractions of VLDL and LDL to the 15 days of cold acclimation. The variations in percenta ge composition of LP occured already on the first day. The changes of physico-chemical features of LP (surface charge and surface area, lipi d viscosity and protein-lipid interactions did not always correspond t o their quantitative changes and were not connected with lipid peroxid ation. The decrease of the charges and the diminution of the surface a rea of VLDL, LDL and HDL were revealed on the first day. At 28-49 days the charges of VLDL and LDL were higher than in control, but LDL' one was lower. The occured at this term decrease of efficiency of fluores cence energy transfer from LP' proteins to lipids, different variation s of lipid viscosity demonstrated the less dip of proteins into lipids and/or the forming the aggregates of protein molecules. These in vivo LP modifications undoubtedly can induce the changes of their receptiv e and regulatory abilities.