[Protective effect of high density lipoproteins, their subfractions and lecithin-cholesterol-acyltransferases on the peroxidation modification of low density lipoproteins]. / Zashchitnoe deistvie lipoproteidov vysokoi plotnosti, ikh podfraktsii i letsitin-kholesterin-atsiltransferazy v perekisnoi modifikatsii lipoproteidov nizkoi plotnosti.

The role of high density lipoproteins (HDL), their subfractions (HDL2 and HDL3) and lecithin: cholesterol acyltransferase (LCAT) on peroxidative modification of low density lipoproteins (LDL) in vitro was studied. Peroxidative modification was estimated by the formation of malonic dialdehyde (MDA) and LDL aggregates during LDL incubation at 37 degrees C for several days without Fe2+ or for 2 hours in the presence of Fe2+ in EDTA-free media. It was shown that the addition of HDL3 (but not HDL2) markedly decreases the formation of both MDA and LDL aggregates. Since LCAT is bound to HDL3, its effect was examined. An addition of LCAT isolated from human plasma (650-fold purification) at a concentration of 450 micrograms/ml resulted in a complete inhibition of LDL peroxidation and LDL aggregate formation. Heat-inactivated LCAT had no effect. Possible mechanisms of the protective effect of LCAT on LDL peroxidative modification are discussed.

[Optimal local hypothermia regimen in the experimental resection of the single kidney]. / Optimal'nyi rezhim mestnoi gipotermii pri rezektsii edinstvennoi pochki v éksperimente.

The morphological and functional changes of the single kidney were investigated in experiment on 133 dogs after removal of 45--50% of its tissue. Resection of the single kidney under normothermal conditions was established to result in the animal's death within 1--14 days due to acute renal insufficiency. The operation executed under conditions of cooling to 25 degrees C is of high risk. Resection under 5 degrees C hypothermia fails to cause an acute renal insufficiency but considerably disturbs the renal function. The use of local hypothermia to 15 degrees C in resection of the single kidney gives the optimal temperature regimen since it prevents the development of acute renal insufficiency and the compensatory-restorative processes in the kidney can develop successfully.