scholarly journals Lecithin-cholesterol acyltransferase (LCAT) catalyzes transacylation of intact cholesteryl esters. Evidence for the partial reversal of the forward LCAT reaction.

1990 ◽  
Vol 265 (5) ◽  
pp. 2665-2670
Author(s):  
M Sorci-Thomas ◽  
J Babiak ◽  
L L Rudel
2019 ◽  
Vol 50 (2) ◽  
pp. 303-313
Author(s):  
Sherazede Bouderbala ◽  
Malika Bouchenak

Purpose This study aims to investigate the effect of Ajuga iva (Ai) on enzymes involved in the metabolism of cholesterol, in rat fed a cholesterol-enriched diet. Design/methodology/approach Male Wistar rats (n = 12), weighing 120 ± 5 g were fed on 1 per cent cholesterol-enriched diet [hypercholesterolemic (HC)] for 15 days (d15). After this adaptation phase, HC rats (total cholesterol = 6.5 ± 0.6 mmol/L) were divided into two groups fed the same diet and treated (Ai-HC) or not with (HC) with Ai for d15. Findings At day 15, in Ai-HC group compared to HC, serum triacylglycerol (TG) values were 1.4-fold lower (p = 0.002), whereas unesterified cholesterol (UC) contents were 1.8-fold higher (p = 0.0001). Serum phospholipids (PL) and cholesteryl esters (CE) contents and liver TG, UC, PL and CE values were not sensitive to Ai. TC/HDL-C and LDL-HDL1-C/HDL-C ratios were, respectively, 1.8- and 4-fold lower (p = 0.006 and p = 0.04). HDL2-C and HDL3-C amounts were enhanced by 40 and 74 per cent, respectively (p = 0.003 and p = 0.0001). HDL3-UC was 1.6-fold higher (p = 0.006); whereas PL contents were 1.4-fold lower (p = 0.003). HDL3-apo and HDL2-CE contents were similar between groups. A decreased of hydroxy-methyl-glutaryl-coenzyme A reductase and cholesterol 7α-hydroxylase activities (−44 and −25 per cent; p = 0.003 and p = 0.02, respectively) were noted. Lecithin: cholesterol acyltransferase activity was 1.5-fold higher (p = 0.001). Originality/value In HC rat, Ai is able to induce hypotriglyceridemia. However, it turns out that Ai may reduce cardiovascular risk by decreasing the reports of atherogenicity and modifying the activities of enzymes involved in the cholesterol metabolism.


1996 ◽  
Vol 271 (6) ◽  
pp. E1073-E1082 ◽  
Author(s):  
R. D. Shamburek ◽  
L. A. Zech ◽  
P. S. Cooper ◽  
J. M. Vandenbroek ◽  
C. C. Schwartz

Metabolism of 1-stearoyl-2-arachidonyl-phosphatidyl-choline (SAPC), a major phosphatidylcholine (PC) species in rat plasma, was compared with 1-palmitoyl-2-linoleoyl-PC (PLPC) metabolism. High-density lipoproteins containing SAPC and PLPC tracers labeled in the sn-2 fatty acid with 3H and 14C isotopes, respectively, were administered. The rats were depleted of endogenous bile acids and infused via the ileum with individual bile acids that ranged widely in hydrophobicity. The half-lives for SAPC and PLPC in plasma were 48 and 57 min, respectively. Most of the 3H activity that disappeared from plasma at 1 h was found in the liver in 1-palmitoyl-2-arachidonyl-PC, SAPC, and 1-oleoyl-2-arachidonyl-PC, indicating phospholipase A1 hydrolysis of plasma SAPC forming 2-arachidonyl-lysophosphatidylcholine, which was reacylated in the liver. Plasma PLPC also underwent phospholipase A1 hydrolysis, as reported previously. The fraction of 3H dose that accumulated in plasma cholesteryl arachidonate was two- to threefold higher than the fraction of 14C dose in cholesteryl linoleate. Multicompartmental models for SAPC and PLPC were developed that included lysophosphatidylcholines and cholesteryl esters. Bile acids did not influence plasma PC metabolism. Lecithin-cholesterol acyltransferase and phospholipase A1 (hepatic lipase) hydrolysis accounted for > or = 90% of the SAPC and PLPC that disappeared from plasma; SAPC and PLPC are comparable as substrates for hepatic lipase, but SAPC is preferred by lecithin-cholesterol acyltransferase.


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