[Acylation of 3beta-(2-hydroxyethoxy)cholest-5-ene in the presence of lecithin:cholesterol acyltransferase from blood plasma]. / Atsilirovanie 3beta-(2-gidroksiétoksi)kholest-5-ena v prisutstvii letsitin:kholesterin-atsiltransferazy plazmy krovi.

3 beta-(2-Hydroxyethoxy)cholest-5-ene in the composition of the micellar complexes with apolipoprotein A1 and palmitoyloleoylphosphatidylcholine was acylated in the presence of lecithin-cholesterol acyltransferase from human plasma. The initial rate of acylation was 6-8 times lower than the rate of cholesterol acylation under the same conditions. The presence of 3 beta-(2-hydroxyethoxy)cholest-5-ene did not affect the rate of the enzymic acylation of cholesterol.

[Metabolism of 3beta-(2-hydroxyethoxy)cholest-5-ene after intravenous administration to rats]. / Metabolizm 3beta-(2-gidroksiétoksi)kholest-5-ena pri vnutrivennom vvedenii krysam.

The intravenous injection of 3 beta-(2-hydroxy-2-[3H]ethoxy)cholest- 5-ene into rats with the cannulated common bile duct resulted in the primary accumulation of radioactivity in liver (24%) and spleen (12%) tissues, bile (7%), and blood serum (15%) after 3 hours. The distribution of 3 beta-(2-hydroxy-2-[3H]ethoxy)cholest-5-ene throughout various tissues was close to that of [14C]cholesterol being administrated under the same conditions. The analysis of radioactive products from blood serum showed that 40-60% of 3 beta-(2-hydroxy-2-[3H]ethoxy)- cholest-5-ene was converted to the acyl derivative under experimental conditions.

[Steryl cellosolves--regulators of cholesterol metabolism in isolated rabbit hepatocytes]. / Steriltsellozoly'vyv--reguliatory metabolizma kholesterina v izolirovannykh gepatotsitakh krolika.

Synthesis of 3 beta-(2-hydroxyethoxy)cholest-5-ene, 3 beta-(2-hydroxyethoxy)cholest-5-en-7-one, 3 beta-(2-hydroxyethoxy)-7 beta-hydroxycholest-5-ene, 3 beta-(2-hydroxyethoxy)-5 alpha, 6 alpha-epoxycholestane, and 3 beta-(2-hydroxyethoxy) -5 alpha, 6 beta-dihydroxycholestane was described. Substances obtained inhibited cholesterol biosynthesis in the rabbit hepatocyte cell culture with ID 50 from 5.5(+/-0.7) x 10(-8) to 1.3(+/-0.2) x 10(-5) M and also to a remarkable extent the cell protein biosynthesis.

[Inhibition of cholesterol biosynthesis in rabbit hepatocytes by 3-beta-(omega-hydroxyalkoxy)cholest-5-enes]. / Ingibirovanie biosinteza kholesterina v gepatotsitakh krolika 3beta-(omega-gidroksialkoksi)kholest-5-enami]

3 beta-(2-Hydroxyethoxy)-, 3 beta-(4'-hydroxybutoxy)-, 3 beta-(6-hydroxyhexyloxy)-, 3 beta-(9-hydroxynonyloxy)-, and 3 beta-(2-hydroxy-2-[3H]ethoxy)cholest-5-enes were synthesized. By means of a spin probe, the influence of the synthesized compounds on the phase transition of dimyristoylphosphatidylcholine were estimated. Time and dose dependences of the incorporation of 3 beta-(2-hydroxy-2-[3H]ethoxy)cholest-5-ene into rabbit hepatocytes (the primary culture) were studied. 3 beta-(2-Hydroxyethoxy)- and 3 beta-(4-hydroxybutoxy)cholest-5-enes were shown to inhibit cholesterol biosynthesis from [14C]acetate in rabbit hepatocyte cultures upon a 24-hour preincubation.

[Effect of 5H-alpha-cholest-8(14)-en-3-beta-ol-15-one on cholesterol metabolism in cultured rabbit hepatocytes]. / Vliianie 5-H-alpha-kholest-8(14)-en-3-beta-ol-15-ona na metabolizm kholesterina v kul'tiviruemykh gepatotsitakh krolika.

The effects of 15-ketosterol on cholesterol metabolism in cultured rabbit hepatocytes were characterized by the following parameters: a) cholesterol synthesis, b) apo B and apo E secretion, c) bile acid synthesis. 15-Ketosterol used at therapeutic concentration (0.25 microM) reduced cholesterol synthesis (by 50%). Marked inhibition (by 70%) of apo B and apo E secretion was observed for this agent. Synthesis and secretion of the total [14C]-labeled protein remaining unchanged. 15-Ketosterol did not influence the bile acid synthesis in primary culture of rabbit hepatocytes. These results are suggestive of a new putative mechanism of hyperlipidemic action of 15-ketosterol by a simultaneous decrease of hepatic cholesterol synthesis and secretion of apo B-containing particles.